We recently purchased a new 350. Last month we requested information on cruising speed. Below is a summary of the responses: Boat rpm-speed Tim 2500-low 7s . Mark 2800-7.2, 2600-6.5to6.8,2000-5.5 John 2800-5.3 TOM 2700-hull speed with a Martec Autostream 3-bladed prop Richard (me) 2800-6.3,2600-6.1, 2400-5.8, 2000-4.8 On reciprocal courses I observed the same SOG at the rpm listed. The tach was checked and found to be accurate. The boat was hauled today to have the fin keel replaced with a wing keel - I took the opportunity to measure the three blade prop at 9 inches from tip to tip and about 6.3 inches from tip of the blade to center of shaft. I want to know why I don't reach hull speed and get the problem corrected. We all have the same engine and transmission (I assume) so what could be different? I do have a 5kw generator and an air conditioner installed but I wouldn't think another 400 lbs or so would slow down the boat a whole knot. What props do you guys have? What are the dimensions of the Martec Autostream prop? Do I have the right prop on my boat? Do you have any ideas? Thanks for your help. Richard