About Us

Coastal Charters is a commercial maritime business based in West Cumbria that has hosted a research and development project called the; WaveAccess. The project encompassed the design and build of a rapid crew transfer vessel for the offshore industry, which will bring significant benefits to operators in terms of cost, time and safety.

The design work which started around five years ago with a clean sheet, has been entirely target focused and designed from the bottom up. We foresaw in the offshore wind industry in-particular, as construction moves further offshore there will be a need for vessels to become faster and more able to cope with larger seas. Stability solutions cannot be achieved by simply building larger and larger craft.



This radical new design will optimise the transportation for up to twelve passengers and three crew. Compared to vessels currently used in the offshore wind service, it will dramatically reduce fuel consumption whilst travelling at around twice the speed and maintaining safety and improving comfort. It will significantly reduce the personnel costs to offshore operators through increased efficiency and reduced lost time and from an environmental perspective there is a reduced carbon footprint in both build and operation. Offshore wind is not the only industry to which the vessel design can bring benefits, It can also be used for crew transfers in industries such as: oil & gas, offshore construction, search and rescue, patrol, medivac, safety boat, to name a few.

With the completion of the design work we recognised that in order to prove the concept we needed to build a prototype vessel. By combining our commercial crew transfer experience and the engineering capabilities of our sister Company, S B Engineering Ltd, fast forward and the result is ‘Tenacity’; as radical in its appearance as in its design.

The vessel brings together proven technologies and systems on to one platform producing a safe and efficient transportation and deployment system for personnel at sea.



WaveAccess Vessel – Tenacity specification

‘Tenacity’ is a proof of concept demonstration vessel

Although the vessel design is to DNV class, ‘Tenacity’ has not been built to class (due to cost constraints)

‘Tenacity’ is coded to operate MCA Cat 2 (could easily upgrade to Cat 1)

The vessel design and on-board technology reduces heave and roll

We are currently developing a ‘zero movement’ transfer system for the offshore wind application; this will be ready soon.



The proof of concept vessel specification:







Displacement (light)

20.5 tonnes

Displacement (heavy)

28.0 tonnes

Design speed (max)

50 kts

Current max speed


Engines 2 N°

Doosan 1200 HP

Propulsion 2 N°

Castaldi water jet TD490 HC

Fresh water

250 L

Black water

250 L


2500 L total (6 tanks)

Fuel consumption

circa 380 L/hr at full power absorption

The design intent is that up to 12 passengers and a max 3 crew can travel safely, comfortably and with minimal motion sickness influence at up to 40 kts in seas of up to 2m. The vessel can equally well be used as a rapid response vessel for both technicians and / or equipment. One of the design briefs was to consider that the vessel may remain at sea, working from an accommodation station where it may be craned on and off the platform, (fully laden), or be entering / exiting a floating dock system.

The design is scale-able for those customers who may require a larger vessel.