I'm almost sure I've seen this pop up somewhere before but for the love of God couldn't manage to find where, so I started a new thread
As AI tends to get in financial problems very often, I believe that landlocked countries like Hungary, Afganistan, Austria and others (shortly, all of landlocked ones

) should not have any reason to start researching sea-related techs. If an AI minister of such country decides to do that, he should be declared enemy of the state and shot on the spot. Some of these techs, like Amphibious Assault Designs for example, are quite expensive and researching them makes no sense...
As I'm not familiar with game mechanics, this might be unfixable but I seriously think putting some kind of priorities or restrictions on AI tech research is a "must do". Restriction is a bit strong word as I don't want to create a situation where a starting landlocked country can't research sea-related tech later when they ceased to be landlocked but if it is possible, maybe you could put some kind of "
extremely ultra low" priority on sea-related techs for starting landlocked countries?