[TorpX]

You can't put too much trust in the game maps. People have reported hitting small islands when warping across the Pacific. In RL, the Navy's charts were not that good, so it is more or less realistic.

Radar doesn't help navigation at all; it doesn't show land.

Could you have been hit by shore guns, or such? That close to an enemy base, I would suspect shell fire, or maybe mines.