The reputable magazine "NAUTICA" talks about our boat and our project.

FEB 2023

Indestructible, unsinkable, flameproof, maintenance-free.

And they don't even need antifouling.

then they are completely recyclable. We are talking about the boats SeaRock in HDPE, an acronym for high-density polyethylene, one of the most common forms of the plastic material.

From shopping bags to pipes, from containers to furniture, garden furniture, everything is made from polyethylene. Even bulletproof vests, bulletproof vests are made of polyethylene, even if it is ultra-high molecular weight polyethylene (UHMWPE). A material also used in the nautical sector to build small vehicles such as canoes or toys using the roto-moulding technique (SeaRock is instead built with semi-processed panels, as we will see later).

panels, as we shall see later) which, however, places a limit on the maximum dimensions of the object and a production bound to a minimum number of specimens. It is no coincidence that a real boat, a 7-metre high-performance boat, is only offered by SeaRock Boats, a Roman company specialising in the construction of exploration boats.

In particular, we are talking about the SeaRock XR7, a small powerboat for exploration boat with a deep V to allow its use even with formed sea in all those activities in which it can be used depending on the deck configuration and outfitting.

So activities such as classic boating, fishing, diving, professional activities. Or as a mega-yacht tender. A powerboat, the first example of which is nearing completion. Incidentally, it must SeaRock's production also includes larger and smaller boats.

larger and smaller boats.

Beyond the aesthetic and functional aspects easily deduced from the images on these pages, let us concentrate on the material of construction, that high-density polyethylene HDPE that determines all those advantages we mentioned on the first page.

advantages we mentioned at the beginning. And perhaps also some disadvantages. Let's go and find out.

First of all, let's start with the construction method, which is very similar to that used for aluminium. It is no coincidence that SeaRock offers its boats in both HDPE and light alloy. But back to HDPE from which the boat is built, for which sheets of HDPE of different thicknesses are used.

of HDPE in different thicknesses, commercially available panels.

These panels are CNC-cut and then interlocked and welded together according to very precise criteria and with carefully studied tolerances. The material, in fact, undergoes significant dimensional changes as the temperature varies, which must be taken into account.

This creates a structural grid composed of keel, bulwarks, mouldings, all made of HDPE and all interlocked and welded together on which, in turn, are welded to the panels that make up the hull. In terms of numbers, the boat has as many as 15 stringers, a 30 mm thick keel thickness, a transom and bracket of even 50 mm, while the bottom and sides are 15 mm. Once the structure is welded external structure, the hull becomes a practically indestructible 'monolith due to the combined effect of the type of material and thicknesses used.

As far as the welding process is concerned, it is carried out using extruders that process the material (the same as the sheets) at low temperatures (around 300 degrees centigrade), therefore with a minimum expenditure of energy and without the propagation of toxic fumes.

This results in a very strong structure in the event of a collision or grounding, as HDPE is an extremely robust and elastic material, capable of extremely robust and elastic, capable of absorbing the energy of a collision (it is no coincidence - as already mentioned - that it is also used to make bulletproof vests). A structure in any case easily repaired with a simple heat gun, even using a bottle cap (it is still HDPE), an eventuality that (it is still HDPE), an eventuality that SeaRock considers highly unlikely.

But the advantages do not end there. HDPE has a specific weight of water, a property which, combined with the buoyancy reserves

This property, combined with the buoyancy reserves built into the hull sides, makes the boat unsinkable. Its durability is over 40 years, it does not absorb moisture and is not subject to delamination or osmosis like GRP and does not

suffer from galvanic currents like metal boats. It is also a 100% recyclable material and the hull could be sold by

weight at the end of its life... if it ever comes to that. Finally, the hull does not antifouling, which we know is particularly polluting and expensive.

In short, many positive aspects which are inevitably offset by some negative ones. As with everything. Starting with

from the weight of the boat in question, which, when empty, will be more than 1300 kg, or the aesthetic aspect which is strongly conditioned by the impossibility of treating the HDPE sheets superficially. In fact the only sheets now available with a UV filter are the black ones.

black and, therefore, the boat can only be black and without frills. At least for now. The result is a very essential, almost 'post-atomic', an obligatory look that may not be to your liking. A unless you resort to wrapping the dead work, with all the limitations related to its durability. And then, as with any pre-processed material such as aluminium, the use of HDPE sheets conditions the shapes of the hull, which must necessarily be simplified and not present double curvatures.

All this makes us realise that we are dealing with a truly new boat, built with a material that is new to the nautical world and with a construction method that has been specially designed construction method on which SeaRock is patent pending. A boat that is designed to ensure maximum safety and withstand extremely harsh conditions of use. A boat for extreme adventures. A HDPE Explorer Boat.