A cabin RIB is a rigid inflatable boat with an enclosed or semi-enclosed wheelhouse. It combines the seakeeping and safety of a RIB with the protection of a small workboat, which is why patrol units, windfarm operators, survey teams and serious leisure owners choose a RIB with a cabin over an open console boat. In this guide we explain how a cabin RIB is built, what separates a good one from an average one, and how to choose the right boat for your job.
What is a cabin RIB?
A rigid inflatable boat with a cabin has three main parts: a rigid hull (aluminium or GRP), a buoyant collar around the sheer (an inflatable tube or a foam-filled fender) and a wheelhouse over the helm. The hull gives the boat its ride and strength, the collar adds reserve buoyancy, stability and impact protection, and the cabin keeps crew and electronics dry. Compared with an open RIB, a cabin RIB lets you work longer days, in colder weather and further from shore.
Cabin RIB vs open RIB vs workboat
| Open RIB | Cabin RIB | Monohull workboat | |
|---|---|---|---|
| Crew protection | Low | High | High |
| Stability and reserve buoyancy | High (collar) | High (collar) | Depends on hull |
| Coming alongside other vessels | Very good | Very good | Needs fendering |
| Long days, winter use | Limited | Good | Good |
| Weight and fuel use | Lowest | Medium | Higher |
In short: a cabin RIB sits between a fast open RIB and a heavier monohull workboat. You keep the collar, which makes transfers and boarding safer, and you gain a proper working environment.
What makes the best RIB boats with a cabin?
Brochures all promise the same things. These are the points we look at as boat builders when we judge a cabin RIB.
1. Hull shape and deadrise
A deep-V hull with a steep aft deadrise cuts through waves instead of slamming on them. As a reference, our Custodian 800C has a 19° aft deadrise and the Custodian 1100C 23.5°. More deadrise means a softer ride at speed in a chop, at the cost of a little more power needed.
2. Hull material: aluminium or GRP
Aluminium is tough, repairable and handles knocks against quays and vessels well, which makes it the standard for professional cabin RIBs. GRP gives a smooth finish and is common in leisure boats. HDPE is a third option for very rough use. We compare the three in detail in Which material for your boat?
3. Collar: inflatable tube or foam fender
An inflatable tube is light and gives the most reserve buoyancy. A foam-filled D-fender cannot puncture and needs less maintenance, which suits boats that come alongside daily. Check the number of tube chambers (the 800C has seven) and the fabric quality.
4. Cabin layout and visibility
A good wheelhouse gives all-round view, room for shock-mitigating seats and space for navigation electronics without blocking the windows. Just as important is the deck aft of the cabin: a deep, secure cockpit is where the real work happens.
5. Propulsion
Twin outboards give redundancy and easy servicing. Inboard diesel with sterndrive or waterjet suits boats with high running hours. A builder should help you choose based on your duty cycle, not just top speed.
6. Certification
For leisure use in Europe a cabin RIB needs CE marking under the Recreational Craft Directive (ISO 6185 for inflatable boats). Commercial use usually means a code such as the UK MCA Workboat Code, or classification rules from DNV, Lloyd's Register or Bureau Veritas. Decide this early: it affects structure, equipment and price.
Common uses for a RIB with a cabin
- Patrol and inspection: police, port authorities and coastguards.
- Crew transfer and windfarm support: the collar makes transfers to vessels and structures safer.
- Survey work: room for survey desks, a moonpool, an A-frame or pole mounts.
- Tender and pilot duties: fast, dry transport to larger vessels.
- Leisure: weekend trips and coastal cruising in all seasons.
Our cabin RIBs compared
| Custodian 800C | Custodian 1100C | |
|---|---|---|
| Length overall | 8.37 m | 10.7 m |
| Beam overall | 2.93 m | 3.6 m |
| Aft deadrise | 19° | 23.5° |
| Displacement | 3,100 kg | 8,500 kg |
| Propulsion | Twin outboards up to 2 × 175 hp, or single 250–300 hp | Twin or triple outboards, or twin inboard diesel with sterndrive or waterjet, up to 1,200 hp |
| Max speed | 33–40 kn | Up to 55 kn |
| Fuel | 2 × 190 L | 1,100 L in two tanks |
| Standard | ISO 6185-3 Category B, MCA Cat 2 optional | Built to DNV HSLC, ISO/RCD or class |
| Typical use | Patrol, tender, survey; fits a 40ft HC container | Patrol, interceptor, CTV, windfarm, pilot, survey |
Need something bigger? The Custodian 1300C is our 13 m crew transfer and dive support vessel. All models are available in our model overview.
Maintaining your cabin RIB
- Rinse hull, deck and collar with fresh water after use in salt water.
- Check tube pressure and seams regularly, or inspect foam fenders for damage.
- Follow the engine manufacturer's service intervals.
- Keep the cabin ventilated to prevent condensation and corrosion of electronics.
- Check anodes on aluminium hulls and replace them on time.
Frequently asked questions
What is the difference between a RIB and a RHIB?
None. RIB (rigid inflatable boat) and RHIB (rigid-hulled inflatable boat) are two names for the same type of boat. RHIB is more common in the USA and in naval use.
Is a cabin RIB suitable for rough water?
Yes, if it has a deep-V hull and is built and certified for the right design category. Always check the category (for example ISO Category B for offshore use up to wind force 8) and the builder's track record.
Can a cabin RIB be built to my specification?
At Essential Marine every Custodian is built to order in Haarlem and IJmuiden. Within each model you can choose propulsion, collar type, cabin layout, seating, electronics and job equipment.
Talk to a builder
Looking for a cabin RIB for patrol, crew transfer, survey or leisure? Tell us about your operation and we will advise on hull, propulsion and certification. Contact Essential Marine.
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