4.5 to 5 knots
If your question is average speed for planning a cruise, the most important input from Nick and Wayne is that they motor at a maximum of 6 knots with a clean bottom. Our max is 5 knots, while our sailing speeds are similar to the ones they quote.I wonder what they feel is a good cruising speed on the motor? But it is certainly over 5 knots. So I would feel confident planning a cruising leg for a 290 at 5 knots, or 50 nm per leg. (We don't normally plan over 10 hours per leg.)My problem with this is that we really like sailing at between 4 and 5 knots. So if the wind will drive us a 4 knots, we are happy sailing. So If I had a 290, I'd feel comfortable planning a 10 hour leg of 45 nm, and planning 50 nm if I really needed to get there, and was willing to motor.We have averaged as much as 6 knots on a leg more than once, but those are the thrills we remember with joy. We have also averaged as low as 3 knots when we were enjoying the sailing, and didn't have far to go.DavidLady Lillie