Oliver - thanks for the comments. I have also discovered that Z37 is also a good regatta boat. A bit long so some obstacles can be a bit tricky, however it has two very good features: being narrow compared to a tug for instance it can get through narrow gaps and also being long it goes like an arrow - very true so no twitching about unlike my main steering regatta boat which has twin screws, a mixer and a bow thruster whcih can be a bit of a hand full at times.
Mark - thanks for the warning, I will probably leave the smoke alone as the hull has very little space for a smoke generator and I would need one with fan assistance as nothing worse than a few wisps of white smoke drifting from a warship's funnel although OK for a Clyde Puffer I suppose.
Robin