Weren't Signatures notorious for rot, late 90's-early noughties? Like a five year lifespan? They realosed they needed to up their game. Caribbeans have a long standing reputation for being rot-free, due to their construction methods and insistence on building a quality product. Unlike some brand manufacturers who were just intent on turning out as many as they could--looking at you, Seafarer, with your masonite floors, (Markham were guilty of that , as well. ) That being said, of course, manufacturers can build them to as high a standard as possible, then some f*wit numpty owner comes along and drills holes clean through to install an auxiliary bracket
, then "seals" the holes with silastic, or sikaflex, and away you go, the moisture is off and running.
The "no wood" policy is a way of dealing with it, but not the be-all and end-all. If you took that attitude, you wouldn't be buying anything from International Marine, who make Caribbean. Since the early nineties, thye have had very little wood in their trailer boats. No wood in stringers? Check. No wood in deck, or foredeck? Check, it's all a GRP sandwich laminate. Any bulkheads wood ?--the forward collision bulkhead is ply, 25mm thick, heavily glassed, and this is not in the water anyway. Cabin bulkhead is solid glass. Wood in transom? Yes, they do, and before you start howling about that, look at how they do it. The wood section of the transom ) made from actual marine ply, not structural, as some did.
Only the centre section, the thick bit, is the ply, fully encapsulated . The outboard mounting holes are drilled before delivery, oversize, filled with epoxy, then redrilled. The rest of the transom is solid glass, drill away to your hearts' content. You can even screw into the very bottom of the section under the ply, because the hull is a solid 25mm thick where it tabs to the transom bottom, so, drilling into that is just solid glass anyway.
So, no wood is a good thing for hull longevity, in that respect, but not an absolute. Anything you buy from a reputable manufacturer, under ten years old, should be good. You are at least getting the rot out of the equation.The problem with that? You are paying near new price. Beware of small manufacturers with attractive pricing--corners will be cut, and they just may go belly up during your build anyway.
As for ali, well, pinholing has been mentioned, but my main concern would be overall build quality. They can look flash, but be a nightmare below, cracking, corroding--stay away from anything ali that touts foam filling as a safety feature, the foam traps salt and moisture against the hull and eats it away. In a glass boat, it will end up a stinking mess. I've had a lot of experience with large ali hulls, and I've seen it all. Paint looks nice for a few years, then fades, dark colours show every scratch, paint bubbles around fittings, it goes on and on.
Why is the new boat shopping " depressing" --cost? Not getting the layout you want? Selling BMT packages with trailers that are barely legal when fully fuelled, without adding any of the gear you carry?