AFT TRANSOMS

Once more, we would like your input so that, together, we can conceive an aspect of catamarans that is as practical as it is aesthetically pleasing, the result of numerous compromises: the aft transoms.

In the design of a catamaran, every centimeter counts, every shape, every component has an impact on the performance, the comfort, and the safety.  It is in this spirit that today we explore the topic of aft transoms of Excess catamarans, which are among their more distinctive elements.  Our objective is to initiate a discussion within the community of sailing enthusiasts to see what ideas might emerge and which creative solutions might be envisioned.

Why are our aft transoms short?

Short aft transoms on Excess catamarans are not the product of chance. They were carefully designed to optimize multiple aspects of our catamarans.

On our Excess 11 and Excess 14, a crucial decision was taken: to move the mast forward of the coachroof. This decision stems from multiple considerations, notably structural advantages, weight reduction, living space in the saloon, and improved performance, due to an increased sail area.  Following this evolution, our product managers found themselves faced with a dilemma:  to fix the aft transoms and shorten the nacelle, and thus the layout, or to move the mast further to conserve a spacious nacelle and long transoms, but in compromising our ratio of 1.5 for the nacelle/hull length overall (article on the boat’s performance by Bruno).  Contrary to the option of moving the mast forward or reducing the length of the nacelle, we chose to place the mast in the optimal location, by moving the nacelle aft, without reducing it, to improve the entire cruising experience.  This evolution then led to shorter transoms, a deliberate choice to optimize the handling, aesthetic design, and accessibility of the catamaran, all while maintaining a long nacelle moved aft.

If you have ever had the chance to sail aboard an Excess, you have probably noticed the short distance between the helm and the water’s surface.  This configuration simplifies handling by offering the helmsman a clear view over the boat’s stern, while also facilitating access on board.  Vincent, with Excess Delivery Services, demonstrates docking maneuvers for us in the Excess tutorial, with an ideal flow of movement via these aft transoms.

However, could they be extended?

Although short aft transoms present numerous advantages, it is a legitimate question to ask if they could be extended to meet other needs, notably space, water access while at anchor, or access to the tender.

At Excess, we have identified multiple systems to extend these transoms:

Make longer hulls:  A simple option would consist of increasing the hull length.  That would enable us to have more spacious transoms, but it would also increase the overall size of the boat, which would in turn lead to a cascade of additional costs and constraints for the user.  In fact, that would mean a larger boat with an artificial forward placement of the mast!  

Transom extensions in fiberglass:  fiberglass transom extensions, like those used on the Excess 11 and 12, could be considered.  They offer an economical solution for elongating the deck without affecting the architecture of the hulls, but they could affect the boat’s aesthetic design.

spaces below or alongside the transoms, to store marine equipment or even docking systems for the tender (inflatable swim platform).

Any suggestions from the Lab Community?  Pencils ready!

Call for Ideas from the Express Community

We invite you to share your ideas, your experiences, and your reflections on this subject.  How would you envision the extension of the aft transoms, and are you a fan of this idea?  Do you have other solutions for making the aft transoms more welcoming, more practical, and more ergonomic without compromising the benefits of a long nacelle?