Hi Dave
I have repaired a few wind-instr. Now fist step is to inspect main control /proc. unit/ for visual water damage.
Just scrapped a box full of assorted marine units damaged by water from tiny leaks to charcoal burn.
Next step, get down transducers, unit from top of the mast and check the pot / wind direction / for
intermittency with OHM meter. It is simple pot with 360degres turn /free full turn - no stopper/ . In most cases it is simple repair.
Get a new one, 3 wires re-solder, recondition the rest of the unit, use silicon grease. Whipping effect of the mast is a killer for even good quality units. cheers Mick