Dunno jordy... aluminium isn't completely corrosion proof.. Apparently if you run an al radiator with straight water, it eventually leaks. I left my al framed motorbike in the courtyard of my house while i went overseas for a couple months over winter. Came back and the parts of the frame with less anodising had developed white furry crap. Took ages to polish it out. I always used to think al was rust proof, but apparently when wet it can corrode. Alls I'm saying is, maybe check with an intercooler shop - they'd know if it was a problem - I'm sure they've done boats before. You know.. ounce of prevention deal..