ORIGINAL: Ron Saueracker
My only point here is that if you seriously believe that CD defences are not overly effective (especially when you are all about correct data etc yet ignore the historical examples of CD vs warship exchanges and embrace pure conjecture regarding how CD systems would have faired, and painting al CDs with the same brush that your CD systems are), this causes one to suspect some of your other assumptions. Frankly, I can't believe your are ignoring facts and relying on what ifs.
The Major problem here is that the game makes no worthwhile differentiation between Integrated Pre-War Coastal Defense Systems and the kind of Artillery placed during the war to defend a coastal position. You just can't compare such things. Oahu or Manilla Bay or Singapore or Tsushima Straits or Vladavostok were all created ass integrated systems over years. They had heavy calibre guns in well-sighted and protected positions interlinked with multiple fire control and spotting positions and controlled minefields supplied with tidal tables and total surveys of the area. Within the area they protected they could bring down very accurate fire very quickly. And whether they were defended in a turret or behind great banks of earth and concrete or simply by being located behind a hill, they were very difficult to spot and engage with any effectiveness. These were VERY tough nuts to crack, and all were delt with by avoiding them or approaching them from overland.
During the war, numbers of medium and light calibre guns were emplaced for Coast Defense purposes. These could discourage light naval forces and provide some protection against landings in the immediate
area. About the BEST result such installations could hope for was achieved at Wake. Light Japanese Naval forces tried to land an invasion force and were beaten off with some loss and a lot of humiliation.
When they came back with better support they were able to achieve their goal. Most of the Japanese held Islands that were invaded had some CD guns of some sort. At no time did they really effect the outcome.
Sometimes these guns (or just artillery that happened to sight it) would open fire on passing ships. Rarely is there any report of success..., though they sometimes caused the ships to give them a wider berth. In test results, the most successfull would probably have been the mid to late war USMC Coast Defense Bns with their improved fire control..., but since by that time the Japanese were in no position to "test" them, no actual results exist. Overall, you could say that these installations were usefull for discouraging light invasions and bombardments, but not for preventing a major efforts by heavy forces.
The best defended area by this type of installation was probably at Normandy, where the landing was made between the heavily defended areas at Cherbourg and Le Havre. The CD artillery caused problems, but didn't stop anything. The guns that were felt to be the greatest threat (the 5 French 155 mm that were supposedly emplaced at Pont du Hoc) turned out to be something of a joke found parked in an orchard with their crews nowhere to be found. Later when US BB's tried to support the attack on Cherbourg they were driven off rather quickly by the Coast Defense System that the Germans had inherited from the French and improved somewhat.