What are you installing the new teak floor over? Are you going over the existing floor, are you screwing the new floor directly to the fiberglass structural grid system or did you put a new sub-floor in before installing the new teak floor?
I replaced the floor ;in my 38 about 6 or 7 years ago. The original teak and holly floor was marine plywood screwed directly to the grid system with stainless steel screws. Thank god it was not glued to the grid because it came up very easy. After taking it up I put a new 3/4 in. marine plywood sub floor down encased in fiberglass, screwed again with s.s. screws directly to the grid. Then, I put a commercial cherry t & g floor down with glue only. After the 6 or 7 years it still looks like new.
The thing I woluld worrry about with real teak if I was to think about glueing it would be the oil in the teak not being compatible with the glue. Other than that I woul d worry about cupping of the teak in the wet environment. Normally in a commercial system without glue one nail is used in the tongue. To be safe and make sure the teak does no cup I would go with two screws countter sunk then finished with a teak bung. That is a lot of work. one of the reasons I glued my floor was to eliminate all the work of finishing the screw holes. Let me know how it iis going.