Does the Kerch Strait provide a defensive bonus when attacking units are attacking across it? If yes, what is the bonus? It is not shown in the terrain table. In all the boardgames I have played on the Russian front there was always some kind of defensive bonus.
So a unit sitting in the straight...being attacked from the west receives no bonus for defense and is not affected attacking west.
BUT a unit sitting in the straight attacking to the east is crossing river and attacking a rough hex. A unit sitting just east of the straight attacking into the straight has a river crossing.
Hope that helps.
You might be able to put a coastal defense there if you so chose.