B class Atlantic lifeboat

Our B class inshore lifeboat is one of the fastest in the RNLI fleet.

Helvick Head lifeboat volunteers at sea onboard their B class Atlantic 85 lifeboat, Robert Armstrong B-874

Photo: Nicholas Leach

Helvick Head lifeboat volunteers at sea onboard their B class Atlantic 85 lifeboat, Robert Armstrong B-874

The current generation of B class lifeboat is called the Atlantic 85 – named after Atlantic College in Wales where these rigid inflatable lifeboats (RIBs) were first developed. 85 represents its length – nearly 8.5m.

There have been three generations of B class lifeboat. The first one was the Atlantic 21, the first RIB to join the RNLI fleet. It served from 1972 until 2008.

The Atlantic 21 was then replaced by the Atlantic 75, which was in service from 1993 until 2022. It has now been replaced by the Atlantic 85, which was introduced to the fleet in 2005.

Helm Dave Riley is stood next to Poole RNLI's B class lifeboat.

RNLI/Harrison Bates

Helm Dave Riley, Poole RNLI
The Atlantic 85 lifeboat is a very capable lifeboat to work with. Whether you’re heading to the scene of an incident, conducting a careful search or carrying out the actual rescue, she’s got all the power and kit you could want.


When it comes to racing to the scene, our B class Atlantic 85 lifeboat is one of the fastest in the fleet; her top speed is 35 knots powered by two 115hp 4-stroke engines.

Although she’s an inshore lifeboat, designed to operate in shallower water, the B class can handle fairly challenging open sea conditions too – force 7 near gale winds in daylight and force 6 at night.


The B class lifeboat is ideal for rescues close to shore, near cliffs and rocks – areas inaccessible to our all-weather lifeboats.

The Atlantic 85 is also capable of being beached in an emergency without sustaining damage to her engines.

Most B class lifeboats are launched into the sea from a carriage, with the help of a launch and recovery vehicle such as a tractor. They can also be lowered into the sea using a davit system (a shore-mounted crane) and some are kept in floating boathouses.


With no wheelhouse on the B class lifeboat, the crew are exposed to the elements at all times and rely on their protective kit to keep them safe and warm.

Many rescues take place at night and can involve being close to dangerous cliffs and manmade structures, or searching caves and crevices.

In addition to night vision equipment, the B class lifeboat carries a searchlight and parachute illuminating flares to light up the surrounding area, helping to keep crew members safe as well as locate those in need of help.

The Atlantic 85 has room for more kit and four crew members compared to three on the Atlantic 75, but both have space for a high number of survivors.

The medical equipment stowed aboard includes oxygen and full resuscitation kit, responder bag and multi-purpose ambulance pouch. The Atlantic 85 also carries a stretcher - the Atlantic 75 can carry one if needed.

The B class has a manually operated righting mechanism in the event of a capsize which involves inflating a bag on top of the roll bar.

Her engines are inversion-proofed so that they shut down should she capsize and can be restarted after she has been righted.

Efficiency and effectiveness

The introduction of the first B class rigid inflatable lifeboat (RIB) – the Atlantic 21 – into the RNLI fleet back in 1972 revolutionised lifesaving at sea.

The speed, manoeuvrability, agility and versatility of these RIBs dramatically improved the efficiency and effectiveness of our search and rescue service considerably. And all three generations of our B class lifeboats have helped us to save thousands of lives at sea.

Our B class lifeboats are built and maintained at our Inshore Lifeboat Centre at East Cowes on the Isle of Wight. The last Atlantic 75 to be built was the Miss Sally Anne (Baggy) B-796 in 2003 and she has been stationed at Kinsale since then.

 Illustration of the RNLI B class inshore lifeboat

Lifeboat category:

Year introduced to the RNLI fleet:
Atlantic 75 – 1993
Atlantic 85 – 2005

Last Atlantic 75 built:

Launch type:
Carriage, davit or floating boathouse

Atlantic 75 – 3
Atlantic 85 – 3-4

Survivor capacity:

Maximum speed:
Atlantic 75 – 32 knots
Atlantic 85 – 35 knots

Range / endurance:
Atlantic 75 – 2.5 hours maximum
Atlantic 85 – 3 hours maximum

Atlantic 75 – 7.383m
Atlantic 85 – 8.44 m

Beam / width:
Atlantic 75 – 2.65m
Atlantic 85 – 2.85m

Draught / depth:
Atlantic 75 – 0.41m
Atlantic 85 – 0.53m

Displacement / weight:
Atlantic 75 – 1.6 tonnes
Atlantic 85 – 1.8 tonnes

Fuel capacity:
Atlantic 75 – 182 litres
Atlantic 85 – 210 litres

Atlantic 75 – 2 x Yamaha 3 cylinder 2-stroke 1.1 litre 75hp outboard petrol engines
Atlantic 85 – 2 x Yamaha 4-cylinder, 4-stroke 115hp outboard petrol engines

Atlantic 75
Hull: polyester glass-reinforced fibre, with marine plywood stiffening.
Inflatable collar: hypalon-coated nylon.

Atlantic 85
Hull: carbon fibre and foam core laminate.
Structure: includes epoxy glass and foam sandwich layup.
Inflatable collar: hypalon-coated nylon.

Number in fleet:
Atlantic 75 – 1 remaining boat at Humber LBS as a boarding boat – no operational boats
Atlantic 85 – Currently 135 in total, 105 at stations, 5 in training fleet and 25 in build, repair or awaiting disposal

All lifeboats have a unique identification number.
The first part indicates the class so B class lifeboats start with B.
The numbers after the dash refer to the build number. So the first B class Atlantic 85 was given the number B-801.

Communications and navigation

  • fitted and hand-held VHF (very high frequency) radio
  • intercom (Atlantic 85 only)
  • onboard global positioning system (GPS)
  • radar (Atlantic 85 only)
  • VHF direction-finding (VDF) equipment (Atlantic 85 only)
  • electronic chart.
Last updated December 2022

Watch our B class lifeboat in action