Rigid-hull inflatable boat (RHIB)
Atlantic 21
Royal National Lifeboat Institution · United Kingdom & Ireland
The first RNLI rigid inflatable, developed at Atlantic College; forerunner of the Atlantic 75 and 85.
Specifications
Hull & dimensions
- Manufacturer / builder
- —
- Hull type
- —
- Hull material
- —
- Watertight compartments
- —
- Length overall
- 7.1 m (23.3 ft)
- Length at waterline
- —
- Beam
- —
- Draught
- —
- Freeboard at bow
- —
- Freeboard at stern
- —
- Displacement
- —
- Gross tonnage
- —
- Net tonnage
- —
- Min vertical clearance
- —
- Height to highest unfixed point
- —
- Height to highest fixed point
- —
- Number built
- —
- Year introduced
- 1972
- Year retired
- 2008
Machinery & propulsion
- Propulsion type
- —
- Engines
- —
- Engine manufacturer
- —
- Total engine power
- —
- Fuel type
- —
- Total fuel capacity
- —
- Fresh water capacity
- —
- Launch method
- —
Members-only
Operating limits (seas, surf, wind), towing and stability data, and detailed engineering specifications are available to Members.
Performance & capabilities
- Maximum speed
- 29 kn (53.7 km/h · 33.4 mph)
- Range
- —
- Endurance
- —
- Crew complement
- 3
- People capacity
- —
- Self-righting
- —
- Self-bailing
- —
- Ice operations capable
- —
- Max ice-breaking thickness
- —
- Medical facilities onboard
- —
Members-only
Operating limits (seas, surf, wind), towing and stability data, and detailed engineering specifications are available to Members.
Operational envelope & limits
Members-only
Operating limits (seas, surf, wind), towing and stability data, and detailed engineering specifications are available to Members.
Source citations
| # | Source | Type | Supports | Accessed |
|---|---|---|---|---|
| [1] | RNLI official website RNLI https://rnli.org/about-us/our-history | official | General | Not yet checked |
| [2] | 1972: Rigid inflatable lifeboats RNLI https://rnli.org/about-us/our-history/timeline/1972-rigid-inflatable-lifeboats | official | year_introduced | 2026-09-30 |
| [3] | Eleven years on: a look at the Atlantic 21 RNLI Lifeboat Magazine Archive https://lifeboatmagazinearchive.rnli.org/volume/48/483/eleven-years-on-a-look-at-the-atlantic-21-rigid-inflatable-lifeboat-some-of-those-who-know-her-well | publication | General | 2026-09-30 |