June 14, 2025:
Last year the U.S. Navy began using GARC, a new unmanned surface vehicle/USV. This 1,600 kg vessel is 4.8 meters long. It has a top speed of 63 kilometers an hour. Range varies from 720 kilometers when travelling at 54 kilometers an hour to 1,300 kilometers when moving at 11 kilometers an hour. GARC was originally designed to search for downed pilots or passengers from commercial aircraft. While awaiting ships or aircraft to complete the rescue, GARC can unload inflatable rafts and other supplies.
The growing availability of inexpensive unmanned underwater vehicles/UUVs has made the future uncomfortable for submarine crews but a lot safer for most seagoing vessels be they military or commercial. Since the 1990s the U.S. Navy has been taking advantage of smaller, lighter, more effective and cheaper electronic components to build smaller devices. This shrinking includes batteries, sensors, communications and software. This has presented unprecedented opportunities.
To make it easier for developers to test new ideas, one UUV manufacturer, Bluefin Robotics, developed a lightweight 6.5 kg empty UUV that is built to have any number of experimental, or production modules attached to the front end. Called the Sandshark, it is a torpedo shaped device that is 60 cm long, 12.4cm in diameter and capable of diving down to 30 meters and operating autonomously for several hours depending on weight of the payload.
Best of all, Sandshark uses open source software that can be easily modified and that is the main selling point. With Sandshark it is possible to quickly develop and test new UUV or Autonomous Underwater Vessel/AUV control software as well as new sensors.
Over half the length of Sandshark is available for a payload. When Sandshark comes to the surface, its GPS and wi-fi antenna can pick up operator commands as well as transmit and receive data. The sail that contains the wi-fi antenna also contains an LED strobe as back up for operators to find and recover a disabled Sandshark. The U.S. Navy developed Sandshark payloads for use by Navy SEAL commando teams and submarines. These payloads are classified but it is known some of them involve Sandshark going on one-way missions.
Sandshark comes after the U.S. Navy has been developing and testing a series of robotic mini submarines since 2009. The navy calls these AUVs because they operate largely on their own. These AUVs are silent, very small, and able to operate on their own for up to a year. The first models were two meters long and weighed 59 kg. They were built to operate completely on their own, collecting valuable information about underwater conditions. What this AUV does is automatically move slowly at 30-70 kilometers a day underwater, collecting data on salinity and temperature and transmitting back via a satellite link every hour or so as the AUV briefly reaches the surface. This data improves the effectiveness of sonars used by friendly forces, making it easier to detect and track enemy submarines. That’s because the speed of sound travelling through water varies according to the temperature and salinity of the water. Having more precise data on salinity and temperature in a large body of water makes your underwater sensors, like sonar which detects sound to determine what is out there more accurate. The first of these navy AUVs could dive as far down as 200 meters and later models were able to go down to 1,000 meters or more.
Sandshark greatly reduces the time and cost for developing new AUV components or software. You can afford to lose them and that is a big plus. Better yet, most new tech developed for Sandshark is dual use so that it has commercial uses as well as military ones.