The bow tube on my old Narwhal came apart from the hull in spectacular fashion probably around 3metres back on the stbd side, and about 1metre on the port hand side. I had the family on board at the time, and we very nearly got very very wet - thankfully my glue job from the previous winter held, and the tube didn't come off right back to the transom. As it was, we had to pile everyone to the back of the boat, and trim the engine right up to keep the water from gushing in.
On a positive note though, it planed very easily, and I maxed out at around 33knots with the 75 Tohatsu bolted to the back. In rougher conditions it got a bit wet, and anyone sitting on the bow locker really felt every ripple
I had a 5m model of early 1990 era, but some of the newer ones I've seen seem to have deeper 'v' hulls at the back end, which would make the general ride a lot smoother, almost like my current Humber which softly goes through just about all waves.