The two inshore classes
The RNLI’s inshore lifeboats work close to the shore, in shallow water, around rocks and in surf, where the big all-weather boats can’t go. Two classes make up most of the inshore fleet, and both are popular modelling subjects.
Atlantic 85 (B class)
The Atlantic 85 is a rigid inflatable boat (RIB): a solid composite hull with inflatable tubes around the sides. It’s the third generation of the Atlantic design, following the Atlantic 21 and Atlantic 75, and it entered service in the mid-2000s. The design takes its name from Atlantic College in South Wales, where the original RIB was developed.
Key figures, based on published specifications:
- Length: about 8.4 m
- Beam: about 2.85 m
- Weight: about 1.8 tonnes
- Engines: twin 115 hp four-stroke outboards
- Speed: about 35 knots
- Crew: 3 or 4
Features that matter to a modeller include the tall A-frame over the stern, which carries lights, aerials and a radar, and an inflatable self-righting bag on top that the crew can deploy after a capsize. Atlantic 85s are launched from a carriage, a davit or a floating boathouse, depending on the station.
D class (IB1)
The D class is a small inflatable lifeboat, and the RNLI has used D class boats since the 1960s. The current version, the IB1, is about 5 m long, weighs around 400 kg, and is powered by a single outboard. It has a top speed of about 25 knots and a crew of two or three.
It’s the simplest lifeboat in the fleet to look at, but it carries more detail than you might expect: a small console, grab lines, a fuel tank, an anchor and an aerial mast.
Finding a kit or a starting point
Dedicated kits for the Atlantic 85 and D class are much scarcer than for the big all-weather boats, and availability changes. Modellers usually take one of these routes:
- A specialist kit or hull. Small makers sometimes offer GRP hulls, resin parts or 3D printed kits for inshore lifeboats. Clubs, forums and model shows are the best way to find current suppliers.
- A ready-to-run RIB conversion. Off-the-shelf RC RIBs are widely available. Some are close enough in shape to be detailed and repainted as an Atlantic. Check the hull length and proportions against photos of the real boat before you buy.
- Scratch-building or 3D printing. The Atlantic’s hull is relatively simple, which makes it a good first scratch-build. Plans, published drawings and plenty of photographs help. See making a model boat hull for construction methods.
- Small-scale accessories. Inshore boats sometimes turn up as resin or 3D printed accessories for dioramas or for carrying on a larger model.
Scale, size and weight
Approximate figures, based on the published full-size lengths and weights:
| Class | Scale | Approx. length | Theoretical scale weight |
|---|---|---|---|
| Atlantic 85 | 1:8 | ~1.05 m | ~3.5 kg |
| Atlantic 85 | 1:12 | ~0.70 m | ~1.0 kg |
| Atlantic 85 | 1:16 | ~0.53 m | ~0.44 kg |
| D class | 1:8 | ~0.63 m | ~0.78 kg |
| D class | 1:12 | ~0.42 m | ~0.23 kg |
| D class | 1:16 | ~0.31 m | ~0.10 kg |
Scale weight is the real weight divided by the scale cubed. These boats are light for their size, so small-scale models can be hard to keep at scale weight once you’ve fitted a motor, battery and radio. Many builders choose 1:12 or larger for a working Atlantic 85, and a larger scale still for a working D class. If you want a D class to accompany a big all-weather model, build it at the same scale as a static or towed boat.
Building an Atlantic 85 model
Hull and tubes
The tubes make or break an inflatable model. They need to look soft and slightly rounded, with the right diameter and a smooth curve round the bow.
Common methods include:
- Shaped foam, sealed and painted
- Plastic or wooden dowel or tube, bent and faired in
- Vac-formed or 3D printed half-sections
Add the details that make tubes look real: the seams between compartments, the rubbing strips, grab lines and their fixing patches, and the RNLI lettering along the side.
Seal the hull well. A fast, light boat can take on spray, and a small amount of water makes a big difference to trim.
Outboards: working or dummy
The real boat has twin outboards, and there are two main ways to handle them:
- Working outboard drives. Model outboard units with a motor in the cowling and a propeller on the leg are available in various sizes (see scale model ship propulsion for other drive options). They look right and steer like the real thing, but scale-looking units that are also powerful enough can be hard to find.
- Dummy outboards with inboard drive. Hide motors and propellers under the hull, with shafts exiting near the stern, and fit detailed dummy outboards on the transom. This gives more freedom over motor choice, but the propellers and rudders won’t be scale.
Whichever you choose, the outboards are a focal point, so they’re worth detailing with cowling markings, steering links and fuel lines.
A-frame, airbag and console
The A-frame is the tallest part of the boat. Build it from brass tube or rod for strength, and keep it light. Fit the radar dome, lights, aerials and the self-righting bag housing on top. Wiring for working lights can run down inside tubing.
The console needs the wheel, throttle controls, instruments and screen, plus the crew seats behind it. These are very visible on an open boat, so they repay careful painting.
Crew figures
An inshore boat looks empty without crew. Suitable figures wear drysuits, lifejackets and helmets, and figures at the correct scale can be hard to find for some scales. Adapting, repainting or 3D printing figures is common. Keep them light, especially on a small working model. Our guide to model boat crew figures covers sources and painting.
Building a D class model
The D class has no rigid hull in the same way as the Atlantic, so a working model usually needs a solid hull shaped to look like an inflatable. Tubes, floor and transom can then be detailed on top. Points to watch:
- Get the tube profile right, especially the upswept bow
- Fit the outboard on a sturdy transom, as it’s the only drive
- Add the small console, grab lines and fuel tank
- Keep it light, as there’s little room for ballast adjustment
A static D class is a simpler project and a good way to practise tube-making before an Atlantic.
Running a fast inshore model
At scale speed, inshore lifeboats are much quicker than all-weather boats. Scale speed is roughly the real speed divided by the square root of the scale. For an Atlantic 85 at about 35 knots:
- At 1:12, that’s around 10 knots (about 5 m/s)
- At 1:16, it’s around 9 knots
That’s lively for a model, so:
- Check your club’s rules. Some waters limit fast boats or restrict sailing times.
- Fit a fail-safe. Set your radio and speed controller so the motor stops if the signal is lost. Our radio control setup guide shows how.
- Practise in open water before you drive near other boats or the bank.
- Watch the trim. A light, fast boat can become unstable or nose-dive if the weight is too far forward.
Colours and markings
Atlantic 85s generally have a dark blue hull with orange tubes, and D class boats are mostly orange. Consoles, A-frames, decks and fittings use greys, black and other colours, and these details vary between boats and over time. Work from clear photographs of the specific boat you’re modelling.
Each boat carries an operational number (B- for the Atlantic, D- for the D class), and many also carry a name and station details. For shades, masking and decals, see our guide to painting a model in accurate RNLI livery.
Display ideas
- A launch scene. A tractor and carriage with an Atlantic 85 on the beach makes a striking diorama.
- A station pair. Many stations operate an inshore boat alongside an all-weather lifeboat. An Atlantic 85 or D class beside a Shannon or Tamar at the same scale shows the difference in size well.
- A rescue in progress. Crew figures in the water or on rocks can tell a story.
For an overview of all the RNLI classes and how to set up a working model, see our guide to radio controlled lifeboat models.