Max Speed

Crompton Marine, as a com­pany, might be new to the world of RIB building, but their key personnel have been around for some time gaining valuable experience in this specialist mar­ket. Neil Davison, the man at the helm of Crompton, piloted the very first Atlantic 21 employed in the North Sea oil industry more than twenty years ago. This is reassuring for, like many of his contemporaries, besides being a builder he is also a user, and therefore understands his clients requirements.

Although RIBS for the most part at least, possess strong overtones derived from their com­mercial past, they have in later years been developed increas­ingly with aesthetics in mind. Pleasing lines, modern well pro­portioned designs and layouts, coupled with attractive colour schemes, now reinforce the fact that the RIB after thirty years of research and development has well and truly come of age.

The Crompton 7.8 SeaSprint, is an excellent example of this second generation contempo­rary form of RIB building. Indeed, the particular craft on test, to my mind at least, possessed a good quantity of the ingredients and very exciting. Finished in a royal blue and brilliant white livery, she gave the impression of being a very substantial machine, well suited to the needs of the se­rious leisure user. This image was undoubtedly further enhanced by the racing styled wrap around bucket seats which further served to set this effect off and the colour scheme in general. One of the most prominent features of course to this craft is the rigid bow, moulded in gleaming white GRP. This unit supports an increased size bow locker and in addition provides greater rigidity and strength to the foreword section of the boat.

There is a difference of opinion among purists concerning rigid bows, some feel they de­crease buoyancy and lift to the fore section of a RIB, plus there is the thought that a rigid bow is a vul­nerable item to have on a craft noted for its fendering characteristics. Despite these views, it has to be said that early skeptics are yet to be proved completely right and while there may be some difference of opinion, the hard nosed RIB is growing in popularity as a valid and worthwhile option

Earlier this year, I stepped aboard the Crompton 5.7 SeaSprint for a short trial and have to confess, I was disappointed. But, our testing of this 7.8 model held no such disappointments. The craft was finished to a very high standard, and gave one the overall impression of great strength and quality of construction. The internal hardware of the boat further confirmed my first impres­sions, with several items worthy of special mention.

For instance, the double A-frame made in 1.5 inch stainless steel, was powder coated in dark blue paint. This I felt, was a nice touch to offset the overall colour scheme. The con­struction of the frame itself ap­peared strong and had a pleasing look about it, plus it was reason­ably low in height; another factor in its favour. The stresses imposed upon masts and antennas are very great indeed aboard a RIB, therefore it is important for all equipment, particularly of this type, to have a low central point of gravity to further reduce strain. The larger and more complex the design of A-frame, the more likely it will be to fail.

The seating, as already mentioned is very stylish aboard this boat, the blue and white piped upholstery offsetting the general colour scheme. Both the rear jockey style seating possessed good internal stowage in their locker sections, and the stain­less steel framed back supports did indeed support the back in both sitting and semi-standing posi­tions. It was good to note also that there were plenty of strategically placed stainless hand-holds for the crews use. This is a detail some­times overlooked in some fit outs, but of course the fitting and posi­tioning of them is crucial to crew safety and comfort

The rally car styled wrap around bucket seats provided one with a very secure position from which to helm or navigate the boat. They were also set at the correct height, which meant you were neither straining to peer over the control console or being urged to stand to see over the bow. The high wrap around backs to these seats also provided good support for the neck and head. Bucket seats lacking this design are not suitable for long distance cruising, as they fail to provide proper support to a seated crew member, and goes to prove that sitting can be more fatiguing than standing if the design of the seat is not absolutely correct.

The control console itself at first glance, may appear to be a straightforward square object holding little in the way of surprises, but here, in actual fact, you would be wrong. For as you will notice in the accompanying photograph, its top section extends back towards the seating pods, allowing not only for a plentiful amount of leg room, but also dive bottle stowage. This neat idea not only keeps these cumbersome items neatly stowed out of the way, but also dispenses with the need for stainless bottle racks and the dilemma of where to put them. Additionally, with the console be­ing set just aft of amid-ships, the additional weight caused by diving bottles here would also mean that the boat would remain well balanced, thus avoiding the difficulties associated with a stern heavy boat.

The double expedition type console features a large hatch to its flat front section, whilst its top surface is about the size of a good sized chart table. In other words there's plenty of room for any manner of navigational aids to be fitted. This particular boat came without a windscreen, but no doubt this item could be installed if required.

The helm and throttle con­trols were well positioned with the height and distance. No need for outstretched arms to control the fluid movements of the power as­sisted steering.

What I particularly liked about this craft was the introduc­tion of afoot throttle set starboard just aft of the control station. Per­haps it might have been a little too far forward for those with shorter appendages, but then again the re­positioning of this item would present no problem. It did how­ever, provide one with a marvelous sense of control, far superior to that of a hand throttle, and was ideally suited to a craft that would be used in heavy conditions where the advantages of two hands to the wheel coupled with the sensitiv­ity of a foot throttle would improve the overall handling of the boat enormously.

Going forward, this size­able craft provided a wonderful amount of free deck space, some­thing that is of a premium in a most RIBS. The dark blue Treadmaster non-slip surface to the deck, coupled with the deep free board, also provided a secure environment in which to move about in. In fact, if you were tak­ing this craft South to the warmer European latitudes, it would be perfectly feasible to camp and sleep in this area. A superb dry locker moulded to the GRP rigid bow utilises the forepeak in a most advantageous way, and at the same time, lends support to a heavy duty stainless steel sampson post.

The most fundamental component of course of any craft, is its hull, and here the Sea Sprint like the other Crompton craft, has been constructed with concave design chines which run the full length of the craft to encourage lift and promote grip in tight manoeuvres. The hull itself is constructed from mod­ern materials and resins which give a strong yet reasonably lightweight advantage. A deep-'V' at the stem of the hull allows the craft to cut through heavy seas, whilst towards the stern the `V' slowly de­creases terminating in a delta conic planing curve. Large watertight compartments are formed either side of the main 260 litre fuel tank which is integrally fit­ted under deck, these of the hull to increase safety and stability.

The all important tubes or sponsons to the craft, are made from military spec. 1,500 gms. hypalon, with lap jointed seams tested to D.O.T. specification. In tear resistant tests, the manufac­turers claim this fabric has proven itself to be almost twice as strong as the lighter hypalon used by some of their competitors. The tubes themselves are bonded to the hull along a 2-inch flange for extra strength and are then supported and bonded to a 3-inch inner tube carrier, this again is supported by conventional pliable hinges. Ad­ditionally at the bow, support is given by the hard nose, which in effect cups the inner part of the tube adding yet greater strength to this part of the construction.

But, I here you ask, how does this boat perform how did she handle? Well, obviously a boat of this size represents a pretty sub­stantial form about one, particu­larly with the seating being posi­tioned quite well aft, it means there's a lot of boat in front of one when you are sitting at the wheel. The single 225hp Evinrude outboard on the stern is a hefty powerpack, and a very able one at that. This particular boat was clocked at 68 m.p.h. in the dead flat conditions, indeed, quite a respectable turn of speed for a hull weighing in at 600 k.g.

The design of the Crompton hull provided a good level ride, plus it was not prone to porpoising when moving off the plane. However, though the re­verse chines may assist in direc­tional stability, it's possible that in heavy conditions they may pro­vide somewhat of a firm ride. Sadly, the conditions on this particular test day did not allow us to assess this matter further. None­theless, what was very evident, was the fact that this boat is enor­mously exciting to drive, and one that would rapidly give the helms­man and crew great confidence. Throughout all her high speed manoeuvres she handled impecca­bly. She is undoubtedly a craft built by people who know what a RIB user requires. I would say the key factors that go towards mak­ing this craft such a pleasure to drive are undoubtedly; the excel­lent seating arrangement; foot throttle control; the correct power to weight ratio; and the good line of vision forward. In general, a most impressive and desirable RIB. I have to admit I was rather taken by this one, and can only describe her as being an absolutely super boat.

Builder
Crompton Marine (UK) Ltd
109 Colville Road
Lowestoft,
Suffolk NR33 9RF

Tel: 01502 597111
Fax: 01502 587444