Carrier Seal

Carrier Seal is an 8-man swimmer delivery vehicle designed for the covert insertion and extraction of combat diver units. It operates in three modes; surface, semi-submerged and submerged.

Carrier Seal vehicles transit at speeds of up to 30kts on the surface before switching to submerged mode for a covert final approach at 4kts. 






Carrier Seal is an 8-man swimmer delivery vehicle designed for the covert insertion and extraction of combat diver units.

Example applications for Carrier Seal include:

  • Delivery of 6-man combat team
  • Host platform for autonomous underwater vehicles
  • Remotely operated weapons platform
  • Harbour patrol vessel
  • Rapid-response anti-piracy craft
  • Mine countermeasure operations
  • A built in breathing system adds extra safety for the divers and enables an extended underwater range
  • Several quick mounts for a variety of weapon systems transforms the craft in to a combat craft

On board sensors and navigation systems work together to provide safe transit and accurate positioning day and night, above or below the surface of the water, regardless of vehicle speed or environmental conditions.

In addition to divers and their personal equipment, Carrier Seal accommodate additional mission equipment such as sensor and radio equipment, ammunition and explosives, survival equipment and supplies. For operations requiring extended range, the craft can carry additional fuel stored in a separate fuel tank or additional battery packs.


Dimensions Weight Crew (Max) Diesel engine Fuel capacity (installed bag) Thrusters Battery pack (basic system)
Length - 10.45m 4300kg 2 pilot + 6 divers 257 kW (350 hp) 360 | (300kg) 2 x 10 kW LiPo (38kWh)
Beam - 2.21m Semi-submerged to 10m depth - 30 s
Height to top of cabin - 1.65m Breaking surface to 25 kts - 150 s
Height to top of activated snorkel - 2.65m Semi-submerged to 25 kts - 120 s
Max draught fully loaded - 0.5m

As illustrated in the Concept of Operation, Carrier Seal operates in three different modes, offering an ideal balance between range, endurance and mission flexibility.

Carrier Seal's two propulsion systems are designed to provide optimum performance, whether travelling at speed on the surface or quietly whilst fully submerged.

SEAL Carrier propulsion.jpgSurface mode

In surface mode, Carrier Seal is propelled by a water-cooled, 345 horse power diesel engine coupled with a Rolls Royce water jet. Together they allow for perfect manoeuvrability. The nozzle of the water jet is controlled hydraulically and is independent of the other hydraulic systems onboard. A reversing gear is supplied.

Diesel fuel is contained within a 360 litre bag located forward of the engine compartment. A second, additional fuel bag may be fitted to provide Carrier Seal with increased range of up to 300 nautical miles.


Semi-submerged mode

To reduce the visible, accoustic and radar signature of Carrier Seal, the vehicle can be operated in semi-submerged mode.

In this mode, the diesel engine and water-jet remain the propulsion system of choice and can propel the craft at sprint speeds of up to six knots. The vehicle’s typical cruise speed in this mode is four knots.

The electrical propulsion system - typically reserved for use in submerged mode - made be used if required.

Air intake is achieved via a hydraulically actuated snorkel. The navigator may raise the height of the snorkel by up to a meter so as to avoid water ingress. Sensors within the snorkel seal the engine capsule and prevent the diesel engine from starting if the presence of water is detected within the air inlet system. When not in use, and in surface mode, the snorkel sits flush to the superstructure.


Submerged mode

The surface propulsion system is contained within a stainless steel casing maintained at a constant pressure. This allows Carrier Seal to transition into submerged mode seamlessly.

Whilst operating in surface- and semi-submerged modes, the diesel engine and onboard generator charge the lithium polymer batteries.

In submerged mode these batteries deliver power to two electric thrusters installed at the vehicle’s transom. This propulsion system affords Carrier Seal a submerged range of 30 nautical miles at a speed of up to five knots. Carrier Seal's typical cruise speed in submerged mode is three knots.

Additional battery packs may be installed to provide twice the range and endurance in fully-submerged mode.




Name Type PDF
Carrier Seal Specification Booklet 230131 Carrier Seal.pdf