submerge in stormy weather or rough seas. never travel on surface unless its calm....the rougher the seas the more your boat has to fight to compensate.....this is modeled in the game.....there aren't actual current flow models but, there are simulated currents that are randomized and relative to wave height...you will see these effects if you try to manuever your boat manually with rudder instead of using a navigator....its like a random force that is applied to the ship in different directions much like the wind as you travel....when you submerge this effect is minimized ....so its better to run electric until the seas calm down....if you are in a bad season...just write off the fuel or stay idle at sea until you come across better weather....you don't need to worry about food reserves...time is on your side
