The Crimea Defence Plan
Our Soviet opponents had amply built up their defences of the Kerch straits so we knew there was no profitable prospect of trying to make an assault crossing to the Kuban. So the sole task our remaining forces was the defence of the Crimea.
A corps of the 1st Rumanian army guarded the straits themselves. But what else was needed to prevent the Soviet side from reestablishing themselves in the Crimea by using naval invasions?
Ultimately any naval invasion would be isolated and could easily be repelled by units railed in on future turns unless
i) a port was captured and held for long enough until it repaired - only Sevastopol could be repaired quickly enough for this to even be a prospect.
Or
ii) the naval invasion could lead to the defeat of the troops holding the straits by isolating them to reduce their effectiveness against cross-straits attacks
Our aim was to prevent this happening, but to do so with the minimum number of units so as not to divert them from the fighting on the main frontline. The team went through many versions of where combat units should be stationed in Crimea or where forts should be built. But after game playing all the possible scenarios we came to the surprising conclusion that nothing else was needed so long as the size 1 port of Temryuk in the Azov sea a few hexes from Kerch was bombed to give it a few points damage.
The picture below illustrates our Crimea defence plan. The red highlighted areas show the only hexes the Soviet team could launch an amphibious invasion on once Sevastopol was repaired and while Temryuk was too damaged to operate.
The nearest they could land to Sevastopol would be six hexes away - and that would be if they walked over mountains. As we will always have units garrisoning Nikolaev and other cities near by, generally combat units needing refit from the front, there will always be units we can rail in the same turn as any naval invasion to intercept them. A turn later and many more units in an emergency could be railed in from other garrisons and the frontlines. Not only could a naval invasion not hold on to Sevastopol until it repaired, it would be intercepted before even getting there. The units isolated from any port would be easy for even allies to defeat.
However the Soviet team could counter this by a seperate naval invasion on the Azov sea coast to cut the rail line on a coastal hex, or 1 hex away from the coast by flipping control through a ZOC. This would only be possible if Temryuk remained a working port - and as a size one port only a small amount of damage would keep it from working. The remaining Soviet ports on the Azov sea of Eysk and Azov itself are too far away to allow an invasion east of Ak-Manay and the Kerch peninsula. So long as Temryuk was bombed to stop it working, no invasion further to the west was possible and units could always be railed in to the peninsula in time to defend Sevastopol.
Our remaining worry was that naval invasions could leave the units defending the Kerch straits isolated by cutting off the land route. It seemed also that a supply route to the port of Kerch through the Black Sea was blocked by the much bigger ports the Soviet side had on the Black sea coast nearby. Full credit needs to be given to timmyab for finding out that the port of Kerch in Axis hands would continue to be supplied from other Axis ports in the Azov sea. Not only did timmyab test this to show it was true, timmyab was the first to even suggest it was possible. Given that the Axis side will always have zero shipping capacity in the Azov sea, however much of the world it conquers, it is surprising that it can still trace supply over the sea.