All it does is float and move.
Turrets don’t move or fire.
If you have DLC or have stock mechanic knowhow, the turrets are straightforward subassemblies that you can remove and place atop a rotating thing if you want them to move.
Turn on infinite fuel if you want it to not fly away after a few minutes.
Roll it into the water at 40 m/s or less on its wheels.
I realize now I forgot to put any steering mechanisms on it.