The S4X2 Twin Boat

The Concept and Basic Figures

In the next months, Wavewalk will develop a twin S4 “quadramaran” boat – a double catamaran featuring four hulls in total.
People have been tying together small and bigger boats for many years, from canoes and kayaks to larger vessels, and the S4X2 will simply be an improved version of this concept.
With its total width of over 80 inches, the S4X2 will be extremely stable and seaworthy, and its estimated load capacity will be over 1,000 lbs, which means that it could carry a driver and three full size adult passengers, plus plenty of camping, fishing, hunting or diving gear. Everyone on board will be able to stand up at the same time as the other passengers, and fish in this position.

Structure

The boat will be made from a pair of Wavewalk S4 multihull boats attached together by means of a lightweight wooden structure reinforced with bolts and  metal brackets. The estimated total weight of this boat is 220 lbs without the motor and payload. This includes two times the 100 lbs that each S4 weighs, and 20 lbs for the wooden structure.

Partial view of an S4X2 multiboat
Partial view of an S4X2 twin boat made from two S4 skiffs assembled together

Portability and Mobility

The main advantage that this boat will offer over other boats of similar size is that even one user could take it apart quickly and easily, and transport it non-assembled without a trailer, if the transporting vehicle is big enough, such as a minivan, a big SUV, or a big pickup truck.
The boat’s easy transportation and assembly capability will greatly enhance hits users’ ability to launch it almost anywhere, without necessarily relying on boat ramps.

Power and Speed

Being stabler and more seaworthy than its individual component boats, the S4X2 could be powered by a bigger outboard motor. How powerful remains to be seen, and current estimates are up to 20 HP, which means that it may reach 30 mph.
Alternatively, two S4 owners could join them together, and power their ad hoc S4X2 with two small outboards normally used separately on each of the S4 boats. In such case, a wooden structure would not be necessary, since the main purpose of this structure is to enable driving the S4X2 with one powerful motor attached along its center line.
Note that the combination of two small motors will not be yield much more speed than each of the small outboards can deliver separately, but it will be more powerful than a single small outboard, and useful to move heavy loads.

Twin S4 Multihull Boat
Top view of an S4X2 multi boat

Versatility

The ability to quickly assemble and disassemble this boat will make it perfect for multiple uses. For example, in a capacity of a tender (service boat) for a big boat, a group of passengers could go on shore in an S4X2 , and return to the mother ship in different times, in two smaller groups, each using a single S4.
Similar scenarios can be imagined for hunting, fishing and diving trips, and tours with people who have different interests and/and schedules.
In this context it is important to remember that the S4 works perfectly not just as a motorboat, but as a paddle craft (canoe or kayak) as well. Carrying a spare, small electric outboard on board an S4X2, or even a small gas outboard will be easy, and doing so could turn the two S4s components into completely independent vessels.
However, if the owner of an S4X2 is interested mainly in versatility, they should bear in mind that a single S4 is not capable of taking a 4-Cycle outboard motor that’s over 10 HP, due to the motor’s weight at the stern. In other words, there will be a tradeoff between maximum speed and maximum versatility.

Skiff Casting Deck

Outfitting an S4X2 with a casting deck will be very easy – just cover the front end with a sturdy plywood board cut to the desired shape.

Sailing

Four hulls for one boat is excessive,  but the exceptional tracking ability delivered by this rare structure, combined by its extreme stability, will be most useful for sailing.

Paddling

Paddling will be very limited in the S4X2, pretty much like paddling is for passengers of a good size skiff or a big Jon boat. This could be a bit of a challenge when beach launching and beaching, especially if there is only one person on board.

Sea Trials

Wavewalk plans to begin a series of sea trials for the S4X2 during the summer. The R&D will focus on testing the strength of the structure, the boat’s performance in rough water, possible need for a spray shield, launching and beaching, carrying the components over short distances, assembly and disassembly, and so on. Bigger motors will be introduced at a later stage.