Non-lethal Devices for stopping Vessels at Sea


  1. There may be a need to stop vessels at sea without resorting to the use of force. This would be useful during peacetime operation such as for VBSS (visit Board, search, Seizure) operations or to stop a boat that is heading towards friendly forces (at sea or in harbor/ anchorage) where the intent of the boat cannot be ascertained.
  2. The vessels so stopped should not suffer any permanent, damage but the speed of the vessel should be slowed down, or ideally the vessels brought to a halt altogether. 
  3. The word vessel is used in its broadest sense and could cover vessels from small, high sped boats to larger ships. 
  4. Boat stopping devices are commercially available which use a pneumatically launched rope with a drogue (sea anchor) which can get entangled with the boats propellers and show down the boat due to the resultant drag. The rope has to be ‘fired’ across the bow of the boat for it to be effectively ensnared. Such a device has limitations such as inability to be used when a boat is heading directly towards the ship which is using the device as in such a case, the rope would lie parallel to the boat path and is unlikely to get ensnared.
  5. For large vessels, a mechanical device such as this may be impractical. A chemical solution may be attempted where a viscous gel – like structure is formed around the vessels propeller thus hindering movement. Such gel should dissipate (or dissolve in sea water) after a certain amount of time.
  6. The solution may be separate or a combined solution may be provided. The means of delivery of the device should also form a part of the proposed solution.