I also go rowing, to be precise - single sculling - in one of those really thin boats. I went down to the river this morning to scull and found the river in flood.So that meant going on the boat club rowing machines. I'm sure these offer the same experience as the cyclist's turbo trainer, i.e. total boredom! Nothing like doing something sort of similar to what you wanted to do - but with the main part of what you like about the activity taken out!