RE: shallow water
u've got a problem there m8. How good is your level and what conditions are you sailing in etc because that 32 cm fin, is waaaaaaaaaaaaay to short for the go155. I own a Go139 and the smallest fin i can use is a 40 cm Select Ride and i need to have the conditions for it, anything shorter and i just get spin outs all the time.
If u'r considering changing boards u can see if the Mistral Ntrance isn't available, big boards with a sword in the middle which compensates for the small fin (it's about 30-35 cm).
If you're already quite a good sailor (u know eg beachstart and harness) then u can even start looking at (depending on your weight) lighter boards.
hope it helps,
Haiko, AKA crazychemical