Send them to the chandlery for a bucket of "Prop Wash". Helps the boat go faster.

First trip with my brother and his wife we motors to the outer Roadtown harbor and shut off the engine. Tim started fiddling with lines, sheets, etc. After a while he says "Huh wonder what this one does?" My sister in law just about lost it. She was sure she was going to die. He was watching the breeze fill in and released the jib to full in just a few seconds, a thing of beauty we were heeled over an underway.