Hello Forum. I'm new here, and thought this would be a good place to ask some questions. Currently at my school, we are building an ROV for a competition. I came here to ask specifically about propellers in terms of sizes, and rpm. Last years team entered the competition without any knowledge of the propeller section, so they failed. Lol. So this year we decided to take it a little more serious. I'll have more information of what power the ROV will be running at (I think it might be 12 Volts) and it's density and buoyancy. If anyone can share any knowledge in terms of an equation for propellers, in relation to RPM and diameter size would be much appreciated. Thanks a lot, Cisco.