The Mine Warfare Morass in UV

[dgaad]

Originally posted by a300mech



Thank you for advising me as to what I can, and cannot be satisfied with dgaad. Most helpful of you. I will rest easy now that you have decided how I feel about this issue.
I will be sure to ask your permission next time I accidently start to develop an opinion of my own.

Funny. Sorta. Have you played against a human player or not? Don't take things so personally.

[dgaad]

Originally posted by Didz


Hi dgaad,

Would you care to explain why you feel mine warfare is an issue in PBEM play?

I suspect I know the answer but not having played PBEM I would be interested in hearing your opinion.

Cudos to Didz for saying flat out he hasn't done PBEM yet.

Didz, the reason is because you can lay dozens of minefields around every port. I"m talking 30-60 hexes with mines, and hundreds of mines per hex. You can also lay them in deep water. Often one or two islands become a center of battle, and the player who lays the most mines winds up in a superior position because to totally shuts down reinforcement and supply. The tactics are totally skewed around the number of minefields you lay and how quickly you can do that. This doesn't happen with AI because the AI does not lay or sweep mines very aggressively, so with that situation you have at worst only a few minefields to deal with while you lay as many fields as you want.

Matrix's "solution" to this issue will be to limit where you can load mines to one fixed location per side : Truk, and Noumea. Also, there will be an increased chance of hitting your own mines as a disincentive to lay so many.

I think this is the wrong solution, and goes too far in the opposite direction, for the reasons discussed in previous posts to this thread.

[Nixuebrig]

Originally posted by dgaad


Cudos to Didz for saying flat out he hasn't done PBEM yet.

Didz, the reason is because you can lay dozens of minefields around every port. I"m talking 30-60 hexes with mines, and hundreds of mines per hex. You can also lay them in deep water. Often one or two islands become a center of battle, and the player who lays the most mines winds up in a superior position because to totally shuts down reinforcement and supply. The tactics are totally skewed around the number of minefields you lay and how quickly you can do that. This doesn't happen with AI because the AI does not lay or sweep mines very aggressively, so with that situation you have at worst only a few minefields to deal with while you lay as many fields as you want.

This is a problem, but.... only against the "I play only to win " players, not against the ones who play cause they wanna have fun.

Greg

[dgaad]

Originally posted by Prince


This is a problem, but.... only against the "I play only to win " players, not against the ones who play cause they wanna have fun.

Greg

Yes, well, its difficult to tell who is who. I'd prefer a game system to handle the issue smoothly and realistically.

[pad152]

Reading the latest info on the patch seems to prove mines will be useless.

From the patch info:
16) Mine fields placed in deep water decay at the rate of 50% per day. These either sink, float
away or the moorings brake.

I agree mine fields should decay but with only being able to load mines from Truk, mining will be made useless, because it will take days or week+ to return to Truk to reload mines. The mines layed will disapear before you can reload.

[Nixuebrig]

Originally posted by dgaad


Yes, well, its difficult to tell who is who. I'd prefer a game system to handle the issue smoothly and realistically.

A game system always offers some exploits, so best is to come to an agreement before starting.

Another solution would be to remove the submarine mine laying missions and let only minelayers lay mines. This would lower the amount of offensive minefields laid.

[Chiteng]

Gentleman PLEASE!

Your forcing me to agree with Dgaad which is upseting my stomach!

First, mines DONT work in deep water. Get over it. It should NOT
happen. PERIOD.

Now if we remove that particular feature, then the worst abuse vanishes. How simple can you get?

Dont complain about which ship carries whatever ordinance,
that is the WRONG direction.

Minefields are by their nature(excluding of course air dropped)
defensive. I dont recall any Jap ships running the minefields
off Brisbane or English ships challenging Heliogoland Bight.

You dont read about it because the enemy knew **** well that they were there and stayed AWAY from it.

Its real easy to get lost in the dark you know? I would hate
to know there were 'freindly' mines lying about if my ship suddenly lost power OR worse weather dragged me into the field.
The 'freindly' mines may not care as much as me about WHO they go off on.

In WW2 mines were NEUTRAL. Either you DID know where they
were OR you didnt. If you didnt, you found out when the loud bang occured.

The limiting factor with mine use was(as I have said before)
POLITICAL. In combination with the fact that I for one have NEVER
seen a comprhensive list of pre-war mine stores and attendant
production leave me with the impression that NO ONE KNOWS.
We are all therefore 'guessing'
If you ARE guessing at least have the courtesy to admit it.

In game terms I think a better solution would be to have mined
hexes flagged as mined with a density given.
I think limiting the number of mines possible per hex is better.
I also think ANY deployed baseforce with sufficient supply should
be the mine depot.

[a300mech]

Originally posted by dgaad


Funny. Sorta. Have you played against a human player or not? Don't take things so personally.

Yeah, too bad ya got your nose bent dgaad. But then of course you did ask for it. Ya gotta expect that kind of thing when you pretend yours is the only valid viewpoint kiddo. :p

Now, if you'll re-read my initial post you'll see that it makes no difference weather I play email, or not. I stated my desire to have the ability to keep mine warfare the way it is with a selection in the preferences page. That way you can have it your way, and I can have it my way. When you arrange to start an email game with someone you merely decide beforehand which option will be used for that game. Ah well, given the info in the patch update
post it seems clear that is not to be. So it is of course a moot point.

[Spooky]

Originally posted by pad152
Reading the latest info on the patch seems to prove mines will be useless.

From the patch info:
16) Mine fields placed in deep water decay at the rate of 50% per day. These either sink, float
away or the moorings brake.

I agree mine fields should decay but with only being able to load mines from Truk, mining will be made useless, because it will take days or week+ to return to Truk to reload mines. The mines layed will disapear before you can reload.

Yep, as you say, mines placed in deep water are nearly useless and it is the objective

Mines were only effective in shallow waters ... wich is not affected by this 50% decay rate

[dgaad]

Originally posted by Chiteng
Gentleman PLEASE!

Your forcing me to agree with Dgaad which is upseting my stomach!

Minefields are by their nature(excluding of course air dropped)
defensive. I dont recall any Jap ships running the minefields
off Brisbane or English ships challenging Heliogoland Bight.

You dont read about it because the enemy knew **** well that they were there and stayed AWAY from it.

The limiting factor with mine use was(as I have said before)
POLITICAL. In combination with the fact that I for one have NEVER
seen a comprhensive list of pre-war mine stores and attendant
production leave me with the impression that NO ONE KNOWS.
We are all therefore 'guessing'
If you ARE guessing at least have the courtesy to admit it.

In game terms I think a better solution would be to have mined
hexes flagged as mined with a density given.
I think limiting the number of mines possible per hex is better.
I also think ANY deployed baseforce with sufficient supply should
be the mine depot.

Chiteng : Sorry agreeing with me upsets your stomach.

Anyway, I agree with you as well. You don't read about mines because they got detected by both sides by and large, with a few exceptions. It was in the effort laying, detecting, and avoiding that is the source of resource expenditure historically, and that gets ignored in wargames because no one has read about it. Its a vicious circle.

I also agree there should be some indicator of density to the side that layed the mines. This is a variable and should change if mines are "thickened" in a particular hex.

Finally, your basic gist about the "political" thing is also correct IF you mean "Operational Flexibility" which is essentially all I am asking for here.

Some people want to handle the issue by agreement between players -- that's not what I am talking about. I am talking about changes to the GAME SYSTEM. You only make agreements if the game system allows exploits or is ahistorical.

Some players want to "leave it as is" or "have a toggle" to turn it off or leave it as it is. That's up to Matrix. But, the SALIENT point here is : lets work out what it should be ideally, then add in things like toggles to turn it off or leave it like it is now or will be in the patch. The way it should be is : expensive mines with operational flexibility on the location of mine centers.

Many posters have made useful comments about operational flexibility about where mines can be loaded, as an alternative to Matrix's proposed hardcoded, arbitrary approach. There are several methods create a more historical situation :

1. A Port / Supply / Cost condition. Port size 4, min 20,000 supplies, 200 (or some other number) supplies per mine.

2. A Mine Warfare "Unit" like an Engineer Aviation unit as is already in the game. I personally like this idea the best. I can't remember who posted it. The number of mines you can load per turn could be a function of the number of "Mine Engineers" or COST, or both.

3. Player designated ports, similar to Barge Hubs, regardless of Port size.

In all cases, to remove the abusive aspects, you need to increase the supply cost per mine.

In all cases, the other changes proposed by Matrix, the increase in hit probability for friendly minefields, the deep water decay, etc. are all good. I just don't like the arbitrary non flexible hardcoded base idea that they've come up with.

[Erik Rutins]

I'm no expert on mining, but I can throw a few thoughts into the debate based on my testing with the patch release candidates.

The main changes to mine warfare since v1.00 are:

- Reloads available only at Truk and Noumea

- Minefields that are in deep water decay quickly and start out quite ineffective (note that in the patch you can now see shallow water locations by pressing F2).

- Minefields that are not at a friendly base or beach location will be considered "offensive", which is another way of saying they are not as well tended. They have an increased chance of hitting your own ships, though it's still much lower than the chance of the enemy hitting them.

- Minesweepers will now sweep enemy and "offensive" minefields.

In v1.00 player reports and my own PBEM experience, I did notice a tendency for certain areas to become quite clogged with mines. Even though deep water mines were very ineffective, they still worked well enough to encourage mass mining. Minelayers would mine the Slot for instance, run back to Shortlands and then mine some more.

I think everyone at Matrix realized that the mine rules were being exploited to a degree and that they needed a second look. Paul Vebber was certainly invaluable in this as he has a lot of experience in this field professionally and was happy to provide a lot of input to the public and development forums.

With the patch changes, I see mining as much less exploitable and more historical. Mining heavily all over the map means you now need to keep minefields from decaying and that you need to sweep your own offensive minefields. This tends to discourage "overmining" in locations that you can't easily maintain, particularly for the unrealistic overmining of deep water hexes.

According to Paul, the US had their mine depot in Noumea through the entire period of UV. I don't believe this would be all that easy or quick to relocate. I know there's concern over Truk as a mine depot. Give the patch a try, see if in the first week or two your concerns are borne out with game practice. If so, and we'll continue to evaluate as well, we can always take a third look.

The only thing I can say for sure is that we keep an eye on things and if we can find a better solution that is not too resource-intensive to implement, I'm sure we'd do it. For now, though, give the new rules a try before closing the book on them. Personally, based on vs. Computer and PBEM play, I'm very satisfied with the changes Mike and Paul have come up with.

Regards,

- Erik

[Slaughtermeyer]

The Australian minelayer Bungaree arrived in Noumea in May of 1942 according to http://www.navy.gov.au/fleet/lpa52manoora/manooraww2.htm
This ship is not present in UV. Australian industry eventually produced over 12,000 naval mines during WW2. This means that either the Bungaree went to Noumea either to get mines from there or else to use Australian-produced mines to mine Noumea defensively. I don't know when Australian industry actually started producing its own mines.

[dgaad]

Originally posted by Erik Rutins
Paul Vebber was certainly invaluable in this as he has a lot of experience in this field professionally and was happy to provide a lot of input to the public and development forums.

With the patch changes, I see mining as much less exploitable and more historical. Mining heavily all over the map means you now need to keep minefields from decaying and that you need to sweep your own offensive minefields. This tends to discourage "overmining" in locations that you can't easily maintain, particularly for the unrealistic overmining of deep water hexes.

According to Paul, the US had their mine depot in Noumea through the entire period of UV. I don't believe this would be all that easy or quick to relocate. I know there's concern over Truk as a mine depot. Give the patch a try, see if in the first week or two your concerns are borne out with game practice. If so, and we'll continue to evaluate as well, we can always take a third look.

I don't doubt Paul's expertise, as I have no reason to. Yet.

However, the issue isn't where the mine warfare ops center was actually located historically during this period, its about the PRINCIPLE of operational flexibilty. I guarantee you if the Japanese hadn't gone after Guadalcanal and the Solomons chain and instead focussed all the action in New Guinea, the Op Center would have MOVED to be closer to it, such as in Townsville or PM.

[mogami]

Hi, Is it possible to detirmine how many mines per month were available per side (like barges and PT boats) They could be created in the same manner.

[dgaad]

Originally posted by Erik Rutins

The only thing I can say for sure is that we keep an eye on things and if we can find a better solution that is not too resource-intensive to implement, I'm sure we'd do it. For now, though, give the new rules a try before closing the book on them. Personally, based on vs. Computer and PBEM play, I'm very satisfied with the changes Mike and Paul have come up with.

Regards,

- Erik

How resource intensive would it be to

1. Create a new class of unit, a Mine Engineer Unit., add that unit to starting locations Noumea and Truk at start of all scenarios. Unit characteristics : 18 x Mine Engineer Squads, 4 x Engineer Vehicles, 24 x Support Squads.

Note : A Mine Engineer Squad is the same as a Support Squad for purposes of combat and construction, and does not provide support of any kind. Its only function is to enable the loading of mines.

2. Code to allow loading of mines only when

a) At least 10 Mine Engineers are present
b) Port Size of at least 2

Errors on attempt to load mines : "Insufficient Mine Engineers" or "Port too small to load mines"

3. Code supply cost to mine loading of X supply per mine (specific number to be worked out in playtesting).

4. Add replacements to the replacements database for Mine Engineers. About 2 per month per side.

Huh huh? Can we spike huh?

This scheme would have zero interface changes, 2 additional text error messages, some validation code.

In addition to all the other changes you have coming up in the patch for mine warfare, I think we'd have a great system.

All of the current issues would be mitigated by the following fallout results :

1. Mines would be expensive. A single mine run might take more than 1000 supplies, meaning you can't do it all the time, and most likely you'll want to keep the MWOC (Mine Warfare Op Center) at a large port with plentiful supplies.

2. Since you have a min port size, you couldn't move it to a pithy island unless you built up the port first, again at a huge logistics cost.

3. Mine Engineers are precious and rare. Best not to place your Mine warfare center in anything except a well protected location. The enemy could bomb the location of the Mine Engineer Unit and cause enough disruption to make it impossible to load mines. Also, the "Malaria Effect" could make it impossible to load mines if a Mine Engineer Unit remains too long in a Malaria zone.

4. MOST IMPORTANTLY : The player has the flexibility to move the MWOC, even if he doesn't need to or want to. But, he CAN if the Operational situation demands it.

5. You save dev cost in WitP, because this system will most likely work there in concept and implementation - you might need to up the replacement levels and add two or three additional MWOCs.

[Chiteng]

Quoting Al Nofti/Dunnigan and in the book 'Victory at Sea?'
or Victory in the Pacific':

This is from memory so bear with me:

Mines were not used extensively in the early stages of the war
because they had no LOBBY. No one was pushing for their use.

No ones career was enhanced by clever deployment. You could never 'prove' anything definatively.

The sub commander WILL get kudos from torpedoeing tonnage.
He DOESNT get kudos for sneaking into Tokyo bay and releasing 50 mines.

No one is standing outside saying how brave they were to go lay that field.

No one denies the 'effectiveness' of the tool of war. Its just that we are all human. We promote things that benifit US.

Sorry for the spelling

(that is what I meant by 'political')

[Slaughtermeyer]

The 55th Battalion Seabees arrived in Brisbane on March 25 1943 and constructed mine depots in the Brisbane and Cairns area according to http://home.st.net.au/~dunn/ozatwar/55seabees.htm
The mine depot near Brisbane is referred to as a "mine assembly depot."

[dgaad]

Johnson, Ellis A., and David A. Katcher. Mines Against Japan. Silver Spring, Md.: Naval Ordnance Laboratory, 1973. 313 pp. -
A record of mine warfare activities in the Pacific Theater during World War II.


" The structure of the Navy's Mine Force has changed dramatically throughout history, in stride with the structure of the Navy in general. During World War II, the Navy's mine warfare assets were in the charge of Commander, Service Squadron FIVE in the Atlantic. Commander, Service Squadron SIX commanded assets in the Pacific Fleet early in the war, followed by the first true MCM type command, Minecraft, U.S. Pacific Fleet. In the postwar reorganization of the fleets, seven type commands were created, each responsible for the condition and readiness of different types of ships, including the Mine Force. In 1946, Mine Force, U.S. Atlantic Fleet (MINELANT) was created. The Pacific Fleet followed suit in 1947, establishing MINEPAC."

Lott, Arnold S. Most Dangerous Sea: A History of Mine Warfare and an Account of U.S. Navy Mine Warfare Operations in World War II and Korea. Annapolis: U.S. Naval Institute, 1959. 322 pp.

From another site :

"The History Locker
Voices From the Past

"We agree that the mine warfare conducted by American planes.....produced a very great strategical effect; it quickly reduced our war potential and hastened the end of the war."

"The mine warfare coupled with the bombing raids prevented our utilizing our war strength and completely nullified our plans to the extent of forcing us to abandon them."

"The results of .... mining was so effective against the shipping that it eventually starved the country. I think you probably could have shortened the war by beginning (mining) earlier.

"Mine warfare, in short, was merely another phase of air warfare."

"Many ship casualties thought to be from submarine attack were actually due to mines."

"I think the planes used in mining were more effective than an equal number used in bombing."

"In my opinion the main reason for the war's ending unsuccessfully.... was the lack of cooperation between the scientists and the military. They (the scientists) got no cooperations."

Taken from the consensus of opinion of all Japanese mine experts as presented by Captain Kyuzo Tamura (later Admiral) at the U.S. Strategic Bombing Survey Conference (1945). The Vice Chairman of the conference was Mr. Paul Nitze, later Secretary of the Navy and Defense, and the interrogator was Commander Tom Moorer, later Chief of Naval Operations and Chairman of the Joint Chiefs of Staff. The mine effectiveness referred to was the 12,500 mines planted by B-29s in the Japanese home waters in the final five months of the war. "

=========

"In April, 1950, Admiral Forrest P. Sherman, Chief of Naval Operations, approved a report from his planners which described mine countermeasures as "...the only countermeasures which seems to offer the possibility of being cheap enough to make peacetime readiness practical." The report went on to warn that "...the great danger is that if mine countermeasures continues to be neglected, large wartime appropriations for countermeasures will be almost useless because the fundamental development will still have to be done first."

In October of that year, after suffering seven ship casualties and having a 250 ship invasion fleet with 50,000 Marines held up for seven days past D-Day off Wonsan, Korea, all due to mines, Admiral Sherman accepted another report. This report, from Rear Admiral Alan E. (Hoke) Smith, Commander of the Amphibious Force, contained the often quoted statement, "We have lost control of the seas to a nation without a Navy, using pre-World War I weapons, laid by vessels that were utilized at the time of the Birth of Christ."

The above was taken from a briefing to senior Navy officials by Dr. Tamara Moser Melia on May 6, 1991 - three months after the Marines had been denied the invasion beaches of Kuwait by mines. "

Guess what? You never read about the hold up of invasion fleets due to mines. I realize this was in Korea, not WW2. But I'm throwing what I have here. This is what I've been referring to as "course correction" or "avoidance". Sucks up massive resources.

=========

From the Office of the Chief of Naval Operations Website :

"Mines in World War II, 1939-1945
As had been the case in World War I, mine warfare played a key role during World War II. Between 1939 and 1945, these weapons sank more than 1,100 Allied ships. The United States alone lost 108 ships sunk and 85 ships damaged.

Axis losses from mines were even more severe. Between them, Germany, Japan, and Italy lost more than 1,300 vessels, with an additional 540 ships damaged. More than 1,000 Japanese ships were damaged or sunk by mines - more than from any other single source.

With numbers such as these, mine countermeasures could not be ignored. As usual, Great Britain led the way with experimentation and research. And again, the U.S. Navy benefited from the Royal Navy's experience. But by war's end, the United States had the world's largest minesweeping fleet and had built up its own experience levels.

Even so, the new generations of sea mines that appeared during the war - and even older types of mines developed earlier in the century - continued to have a significant influence on naval operations throughout this global conflict. World War II featured significant improvements in mine countermeasures, particularly against the moored contact mines that essentially were carry-over weapons from the previous war. However, while the Allies could contain or work around the threat posed by new influence mines that emerged during the war, they never decisively neutralized them.

=======

More from the Chief of Naval Operations Website :

"MCM Operational Lessons: The Pacific
U.S. and other Allied forces in the Pacific also faced a daunting mine warfare task. Fortunately, the Japanese rarely used mines offensively, mainly confining their activities to laying defensive fields - many of them off their own coast. Japanese forces used some German-type magnetic mines, but most of the weapons they laid were copies of old British contact mines.

For many operations in the Pacific, U.S. minesweeping task groups consisted of small yard motor minesweepers, fleet minesweepers, and destroyer-minesweepers conducting exploratory sweeps in front of the assembling assault forces. From 1942 until 1944, these mine countermeasures craft were assigned to Service Squadron 6. But in October 1944 they came under the administrative and operational command of Minecraft, Pacific Fleet - commanded by Rear Admiral Alexander Sharp, who had voluntarily gave up one star to take command of this centralized mine command.


RADM Alexander Sharp

Service Squadron 6 continued to grow throughout the war so that by the invasion of Okinawa in April 1945, Sharp controlled the largest minesweeping force in the history of the U.S. Navy. Moreover, as noted by Chief of Naval Operation Ernest J. King, minesweeping operations at Okinawa occurred "on a scale greater than in any previous operation." Admiral King's report to the Secretary of the Navy, described the mine clearance operation off Okinawa:

The mine sweepers were in the van, and on L-minus-8 day [eight days before invasion], 24 March, commenced sweeping under cover of gunfire from battleships of the Fast Carrier Force, and continued this work up to L-day, 1 April. There were 75 sweepers; and the entire coastal perimeter of southern Okinawa was cleared of mines during this pre-assault phase, in addition to the sweeping necessary for the capture of Kerama Retto and Ie Shima. Including re-sweeping, over 3,000 square miles were swept and declared safe prior to L-day. Some 177 mines were swept and about 80 floaters destroyed. The thoroughness of this task is evidenced by the safety with which bombardment and assault ships in great numbers closed the assault beaches without significant loss from mines.

Okinawa may have been the largest minesweeping operation in the Pacific, but the severest test came in June 1945 before the Australian amphibious assault against Balikpapan in Dutch Borneo. Here, Allied mine forces faced a deadly mix of Japanese contact mines and various types of influence mines laid earlier in the war by U.S. and Allied forces defending the area. Several of these fields were also covered by Japanese coastal defenses. All told, the Allies spent sixteen days prior to the 1 July invasion clearing mines, with the bulk of the work being carried out by the U.S. Navy's versatile, wooden-hulled YMSs . Nevertheless, the high-quality target detectors on previously laid U.S. mines sank seven of these vessels, while several more were destroyed or damaged by Japanese coastal guns. The waters off the assault beaches ultimately were cleared, but at high price.

As was the case in the Atlantic, conditions in the Pacific theater also led to innovations in minesweeping gear and techniques. The MCM craft doing pre-invasion sweeping required the ability to do so quickly and in shallow water. To this end, they were fitted with lighter minesweeping equipment adapted from German gear by Mine Station Solomons Island. Minesweepers in the Pacific also used an NOL-produced towed electromagnetic detector capable of finding mines buried in shallow water off invasion beaches. Meanwhile, the Navy Electronic Laboratory in San Diego developed QLA, the first mine-hunting sonar, in 1944. Nine U.S. submarines were fitted with this system, allowing them to navigate more safely through Japanese mine fields.

U.S. mine countermeasure developments were not all technology-related - some of the most effective were decidedly low-technology. An example of this can be found in the wartime work of U.S. divers in both the Pacific and the Atlantic. Closely integrated into all pre-invasion mine clearance operations, Explosive Ordnance Demolition (EOD) divers usually disposed of mines discovered by other minesweeping units. EOD and Underwater Demolition Teams (UDT) also examined the approaches to selected assault beaches in the days before a landing took place to scout for enemy mines and to mark swept channels. These activities sometimes took place under fire - UDT swimmers reconnoitering the waters off Iwo Jima in February 1945 came under intense fire when the Japanese responded to the presence of the landing craft supporting their operations. "

Dgaad notes : This is another example of the ENORMOUS resources that must be expended to "clear" areas of suspected minefields. Its not insignificant, and has a MAJOR tactical impact on operations.

========

Rather than post bits and pieces of the Chief of Naval Operations site which has good information on Mine Warfare Operations in the Pacific in WW2, I encourage everyone to go to this link :

Office of the Chief of Naval Operations (USN) Website

=======

More coming as I find it.

[dgaad]

Here is a link to a listing of all Minecraft Ships of the US Navy in the Pacific and Atlantic during WW2. Note the number of THESE ships lost to mines, and the locations of their strikes being all over the place :

Minecraft Ships of the US Navy

[Didz]

Originally posted by Spooky

Mines were only effective in shallow waters ... wich is not affected by this 50% decay rate

An added problem being that at present its not possible to be 100% certain whether a hex is classed as shallow or deep for mining purposes. Matrix have confirmed that the water colouration on the map is not an accurate indication of water depth. So laying mines is a bit Hit & Miss at the minute.

Having just read through the excellent postings already made here from dgaad and Erik I note that this is being sorted out in the patch and in future you will be able to determine a shallow water hex by pressing F2.