>I can believe that the mental adjustment would be a nightmare.
>Granted you're still fighting in three dimensions, but beyond that...

I think its more to do with the adjustment between "I am the fastest coolest thing around to "lets go have a drunken brawl in fresh custard whilst wearing sunglasses" in terms of the way the mecha would react in the two mediums, recalling most pilots are used to two media - vacuum and air, water might just strain them a little.

The visibility would be a bit of a non starter, and the sonar etc would report tactical data in a very different manner to the more standard radar kitouts used by the pilots of ye good old fashioned vf1 "brownie"

sounds like fun though

Kathy