In my creation of a semi-realistic armed forces for my world's main faction, I took the unrealistic decision to make a way of keeping battleships. To that end, I adapted my existing idea of creating a 'magic' interdimensional plane, which is effectively a large ocean that allows for interplanetary travel.

One established condition in this plane is that the air is too 'stormy' for aircraft like planes to function properly, or for long range missiles to be guided accurately. However, I can't think of an equivalent set of properties that would make submarine warfare constrained to planetary bodies of water, leaving the Warp to conventional surface combatants.

TL;DR
What kind of properties would this large sea have that would make submarine's incapable of being used as effective weapons?