From OpenROV:

OpenROV Trident Features:

Depth: Capable of 100m (will ship with a 25m  tether - longer tethers will be sold separately)
Mass: 2.9 kg
Top Speed: 2 m/s
Run Time: 3 hours

Connectivity

The data connection to Trident is a major evolution from the connection setup of the original OpenROV kit. It uses a neutrally buoyant tether to communicate to a towable buoy on the surface (radio waves don't travel well in water) and the buoy connects to the pilot using a long range WiFi signal. Using a wireless towable buoy greatly increases the practical range of the vehicle while doing transects and search patterns since a physical connection between the vehicle and the pilot doesn't need to be maintained. You can connect to the buoy and control Trident using a tablet or laptop from a boat or from the shore... (preorder $1,199.00)