Unless you changed AmphibWaveRest, it is too bg for infantry. It is meant for the hovercraft. See my
naval map.ini for a bunch of particle systems made for swimming infantry that look nicer.
That map.ini also has floating naval construction yard, a supply prison, lots of swimming infantry, a movable aircraft carrier, and two types of submarines, one fires long range supercavitating torpedos and the other fires an ICBM with smart MIRVs. ANd all the boats are modded, you can build 6 or 7 types of boats including 2 types of PT boat and a battleship.