Rotor-Rig Marine Design
Racebox is a race signals and finish timing program for sailing clubs. It uses a USB relay to control the hooter sound system and uses either the traditional 10-5-Go sequence or the common 5-4-1-Go sequence. It is easy to use, free and open source.
On the Fittings page is a directory and images of the Rotor-Rig custom hardware for dinghies.