ETAP have reason to rejoice, because in 2005 ETAP Yachting celebrated their 35th anniversary. 35 years of producing safe, unsinkable yachts have made ETAP a world leader in its field.

Since its foundation 35 years ago, ETAP Yachting has been the leading manufacturer of unsinkable yachts.

ETAP sailing yachts are the only recreational sailboats in the world certified unsinkable by the French Merchant Marine, the only official body in the world authorised to issue certificates of unsinkability for sailing yachts.

ETAP is the only builder of sailing yachts in the world to have received this prestigious, complex certification. The yachts must pass an extremely rigorous set of standards and qualifications to receive such certification.

In general, the yachts must not only be unsinkable (meaning they must remain afloat when completely filled with water) but they must also retain sufficient freeboard and stability to actually be manoeuvrable under sail even when filled with water, and be able to progress through the water to a safe destination. When the yacht with crew and equipment on board is flooded, the remaining freeboard must not be less than 3% of the LOA. The yacht must be able to recover from a 90 degree knockdown with a full crew's weight on the lee rail even when filled with water.

One of the important features of the unsinkability being built into the yacht is the safety of unsinkability will always be there, no matter whether you are awake or not, whether you stay calm or not. The closed cell foam does not require any maintenance; it becomes a safety feature that you never have to think about; it is always there and in perfect condition, even after many, many years.

Because of the exclusive ETAP engineering principles applied, the positive buoyancy of the yachts is such that in a completely flooded condition, the water rises only to about the level of the settee height in the saloon (about knee level for an average adult). The rest of the boat remains above the flooded waterline. Even in this condition, a crew may be able to cook hot meals, dry out bedding and clothing, keep foodstuffs from being contaminated, etc.

From the very beginning ETAP opted for technological innovation: unsinkability, sandwich construction, polyester laminate, aluminium deck fittings. Though this certainly increased the number of technical problems, these options proved to be of overriding importance to the company’s later commercial success. The company now has one of the most modern shipyards in Europe.

ETAP builds their boats with full double hulls and polyurethane foam with a minimum 95% closed cells injected into the space between the two hulls, providing sufficient buoyancy to ensure that the boat will stay afloat even if it suffers serious damage.

Both hull and deck are formed using an outer shell and an inner liner. Before the liners are bonded to the hull, their inner surfaces are sprayed with foam in places where the injection operation might fail to reach. The inner hull is laminated in the outer hull and the inner deck into the outer deck, thus forming the unique ETAP ship-in-ship structure. A few strategically placed holes are then cut in to the liner through which the foam is injected. Because the foam reaches a specific weight of 50kg per m3 and expands at an alarming rate during its formation, stiffening moulds have to be clamped into position over the liners so that they don’t distort.

A total of volume of 7m3 of foam is contained in the 37s which provides 7 tonnes of buoyancy. It is distributed in the bows under the forward berth, inside the stiffening framework, at the backs of the settees in the main saloon and underneath the cockpit sole. The positioning of the foam starts at the design stage; which allows ETAP to store the foam in a very intelligent way i.e. in areas where was no useful storage space (e.g. under the stringers). With the company’s knowledge and experience which has been built up over 35 years, they manage to build an unsinkable yacht which has got exactly as much useful storage space as any other not unsinkable, single skinned yacht.

As the foam has a closed-cell structure, every cell renders a floating capacity and … every ship becomes thousands of millions of cells !

This is an exclusive engineering process. Only ETAP Yachting builds recreational sailboats this way as the process is difficult to engineer and makes the production process intricate. Also, it costs probably 30% more to build an ETAP than a single-skin boat of a similar size.

The current ETAP production programme comprises the trailerable ETAP 21i and ETAP 24i, the ETAP 28s, ETAP 32s, ETAP 37s and ETAP 46DS. More than one yacht leaves the ETAP shipyard every day.

The same basic principles which were established in 1970 are still valid: safety, quality, innovation and recreation pleasure and the assurance that when you buy an ETAP you have 100% certainty that it will stay afloat when it is flooded. You must always have confidence that all safety devices installed on your boat are going to really work when you need it.

Since 1970, ETAP, Belgium's biggest production boat builders, have attracted thousands of clients whose prime consideration is for safety through unsinkability.  There is an undeniable logic about the concept of an unsinkable boat.  Everybody who sails loves to be on the sea but dreads the thought of an abrupt & unwelcome dunking in it, miles from land & help. Life raft & panic bag are unsubtle reminders that only half an inch of GRP separates the crew from the depths.  Happily, most of us are able to ignore such thoughts; we know it is possible for the boat to sink, but are confident that it won't.  However, there are some for whom faith is not enough & for them the only recourse, if they want a good sized cruising boat is an ETAP.  ETAP YACHTING has built more than 7,000 of its double-skinned, foam-filled boats over the past three decades. 

What is Unsinkability?  
ETAPs are certified as unsinkable by France's Marine Marchande.

To meet its standards, a yacht has to reach stability & floating requirements.

•    When flooded, the boat's freeboard must not be less than 3% of its overall length
•    A flooded boat must float in a 'practically horizontal' position
•    A flooded boat with maximum crew must right itself from a 90 degrees heel
•    A flooded yacht must be capable of being sailed
•    The trickiest component of these requirements is the self-righting aspect; if the buoyancy was concentrated in the lower parts of the hull, then the yacht would tend to stay inverted.  Therefore, plenty of foam is required in the topsides & deck, as well as in the bottom & ends, volume which could otherwise be used for stowage.

Hull & Deck Moulding

Both hull & deck are formed using an outer shell & an inner liner.  Between these, closed cell polyurethane foam is placed, either in panels, pre-sprayed onto the inner surfaces before the two moulding are bonded together, or injected into the larger hollows between the two skins.
The outer skin of the hull is laid up in a conventional way.  A sprayed-on sanitary quality gelcoat (it's also used in jacuzzis) is followed by a precisely controlled application of resin & glass, mixed & applied by a chopped/spray gun.  ETAP have invested in low pressure (35kb per cm2) Venus equipment which, among other things, applies resin in larger droplets than normal.
The spray guns are also connected to a numerical counter, displayed in liquid crystal form on a read-out mounted on the spray booth wall.  This tells the operator precisely how much material he or she has applied to the mould & should allow him to match the laminating schedule to within a few grammes per square metre.
As soon as the lay-up schedule is complete, the hull is released & moved to a separate working mould.  Bulkheads & chainplate anchorages are then bonded to the hull before the first of three inner liners - which extend to within a foot of the sheerline - is lowered into position. The amidships liner incorporates a stiffening framework of hollow, top-hat sections which take keel & mast loads.
Before the liners are bonded to the hull, their inner surfaces are sprayed with foam in places which the injection operation might fail to reach.  A few strategically placed holes are then cut into the liner through which the foam is injected.  Because the foam reaches a specific weight of 50kg per m3 & expands at an alarming rate during its formation, stiffening moulds have to be clamped into position over the three lines so they don't distort.
The same process is applied to the deck.  In both cases, it is crucial that all electrical conduiting (carried mainly in the deck) & other pipe work like heating ducts are installed before foam injection takes place. 
A total of volume of 4m3 of foam is contained in the 32i which provides four tonnes of buoyancy.  It is distributed in the bows under the forward berth, inside the stiffening framework, at the backs of the settees in the main saloon & underneath the cockpit sole.
Another advantage of a foam core is excellent insulation, which reduces noise transmission & condensation to almost nothing. 
 

 Fit-Out

Styling below decks is distinctive.  A lot of light-coloured oak is used, but cherrywood is also available.  Polished stainless steel grab handles, marble-effect Corian & plenty of portlights are hallmarks of the ETAP range.
The deck, complete with its liners, all light fittings, hatches, deck fittings, non-slip material, pulpits, grabrails & cleats is lowered into place as one of the final production processes.  It is bonded, riveted to keep it in position while the rubbing strake is offered up & then through-bolted.
To save time & improve accuracy, ETAP use a laser beam to determine the position of the boot topping stripes in relation to the waterline.  The beam is shone onto the hull describing a perfectly straight line & then the yacht is levelled on its hydraulically adjustable trailer.  A job that would normally take hours & then be inaccurate, now takes moments & is perfect.
The boat is then lowered into pool & subjected to a 24-hour water-tightness test.  Having passed that, the boat is then shrink-wrapped in plastic before its lorry ride to the coast.

 Evolution

ETAP evolution has been slow & measured & always with an eye to the future. Naval architects - Van de Stadt & Jac de Ridder in the early days, latterly Philippe Harle & Martain / Mavrikios - design the hulls, but all the research & development is carried out in-house, where the CADCAM operators reign supreme.  Special software was commissioned to control every part of the build process.  Boats are built in runs of 15 & the computer will pre-order every component in advance & ensure the right bits & pieces are delivered to the relevant stage of the production line each day.  Materials are accounted for down to the last nut & bolt.
This efficiency extends to the working environment.  Temperature & humidity are strictly regulated to provide optimum conditions for the curing process.

 Summary

The many advantages an ETAP Yacht has to offer can be summarised as follows:

Unique Technique:

ETAP Yachting uses a double mould construction in which a 2-component polyurethane foam is injected.  This foam is called "closed celled" because it is not porous & can hardly absorb any water.  It gives sufficient buoyancy to the yacht in case of a leak to keep it afloat under all circumstances.
An ETAP that sprang a leak will "float" horizontally & will maintain enough stability to keep aboard safely.  In this way the fault can be remedied depending on the situation & a port can be reached under power or with the help of a third person.
Further Assets:
The double moulded construction offers many more advantages:
 

• An excellent thermal & acoustical insulation.  ETAP Yachts are practically condensation free, also in spring & autumn.  Therefore the interior is pleasantly dry & silent
• A stiff construction gives more stability to the construction
• A beautifully finished interior in structural polyester with easy maintenance; no water-fearing materials
• A high re-sale value because of the good ageing of ETAP Yachts.