Thank you for your responses and apologies for the late reply.
My preferred models would be sail boats of some kind that could be used on the water not static models. Mind you, having said that, I haven't got my little Footy wet yet as the only place that I can find locally to sail it is the local estuary and feeder river. I have tried contacting my local council to find out about boating ponds or lakes but having been 'forwarded' to the 'correct' department several times have never had the benefit of an answer. Mind you I did see a recent press release from the council about them going bankrupt and having to put up fees and charges one of which was the £10.85 to sail at a particular leisure park. Now whether that is a hourly, daily or annual charge I don't know but personally I can't see it solving their money problems somehow.
One drawback that comes with that idea is that of boat recovery if something goes wrong. I am leaning towards something like a small airboat as it should avoid any potential weeds and similar things.
As regards materials I tend to favour balsa and ply although some of the larger model that I've looked at do seem to have a GRP skin for protecton. But I prefer to build a hull as against having a preformed shape to work from.