At the last SSMBC (Seminole, Florida, U.S.A.) Jim brought his RC scale model of the "Blue Devil" (WWII Fletcher Class destroyer) to the SSMBC meet. Having taken a video of it I decided to have some fun and edit it and add some sound effects to represent it looking for a German U-Boat. About 2-1/2 minutes long).
Sound layers added: Water, engine, sonar, alarm, and voice.
Lew

Perhaps not a boat, but no pond is complete without one of these gems.
This lighthouse is fully remote controlled.
The lamp rotates at 12 rpm allowing a flash of light every 5 seconds.
A 5kg weight is mounted under the island and winched down to the bottom of the dam to anchor the island. The winch is powered by a 6V Ryobi Cordless Screw Driver's gearbox and motor.
The Fog Horn is operated by a 9V motor with a counterbalance causing a vibration inside the tower, amplifying the sound effect of a steam horn.
It's built at 1:35 scale and stands 80cm tall.

Both boats are 1/24 scale The E boat belongs to a good friend. it has just had a new camouflage pattern added. The Fairmile D is scratch-built, it took nearly 4 years to build, launched in 2011. The sound effects were added for fun. The location is Albert Park lake in Melbourne, Australia

This is my M.F.A Tracker . When originally purchased it had the large and heavy 850 motors in it and old electronics , after a close call with a fire on board I decided to refit her out with modern Brushless motors and over rated Escs powered by Lipo's . Works out a 1/3 rd the weight 3 times the speed and run time over an hour . So a great result

Oh yes , sound effects donated by nearby Tug 😊