I don't think I will be trading in either of my vehicles for a Golf, next time I am down that way I will take a piccy of where I launch my boat from to show why
As a general observation (not specific to boats) I would be a bit wary of regularly towing near the max capacity of the vehicle. Power is one thing, but if the tail starts wagging the dog or if you have to stop in a real hurry, life can get very interesting very quickly. You can get away with lots of things (I've towed a 4 wheeled trailer weighing about 2 tons with a quad bike for example, not on a public road I hasten to add... and both going up and going down hills was "interesting"...) but lots of spare capacity and a fair bit of weight is good to have when things go pear shaped!
But certainly ok for "the odd short trip" - don't know about yours but according to the book my boat is ~350kg and engine is ~150kg so even with fuel and stuff its only going to be about 600kg, with a normal trailer I guess you'd be looking at a ton or so all up weight for a 5.5-6m RIB?
My trailer probably weighs twice as much as the boat but that's another story