We had an idea of marine high power electric propulsion. We believed that in few years there would be a need for this type of products on pleasure marine market. We also knew that it would be difficult to get into the market with high power where large energy storage systems would be used. At the same time costs of propulsion were more acceptable for truly luxury yachts. This is the moment when we started looking at shipyards as potential partners for cooperation and development of boats that will have their own niche in a market.

After two years of developing the 60' cat, we have found a good solution for higher power. Visedo motors were able to provide 400kW continuous power. The system needed 800kW in total. With this opportunity we decided to have a look at the concept of power boat. We ended up with 57’ monohull with 2 x 400kW motors and a diesel-based variable RPM range extender that could provide a steady 390kW of power during the extensive work. With this, we reached ~30kn just on batteries and ~15kn of cursing speed on range extender only.

We decided that the building process would start relatively quickly. After searching for a partner for a long time, we decided to start our cooperation with Latitude Yachts based in Riga. It was not easy to find a shipyard that could handle such a complicated and challenging project. From the propulsion point of view, we had a  system that suits super yachts sized 150’. At the same time, as we were aiming for the highest quality, normal shipyards in our boat size range were far away from super yacht finishing quality. This is how we ended in Latvia, and we cooperated well.

The boat exterior and all machinery was done. Due to COVID, the first sea trials were delayed. We were doing tests of the entire system assembled in our lab to ensure that all worked fine and that software development was going in the right direction. We tested each of our hardware to its maximum operational loads, and we overloaded everything. We gained knowledge on what can happen in many different safety situations. In the end, we had made 6 months of dry tests of our system (with assembled hardware). Once we reached the moment when nothing else was possible on the dry test, we installed all components on a boat in the shipyard.

We faced the fact that large power motors are not widely available. Since we did not want to develop our hardware by our own, we decided to limit our propulsion to only 2 x 250kW continuous output. With this available power, we would create an ultimate design of 60’ catamaran. At that point, we realized that there was a need for a high power DC charging system for boats with massive battery banks that were significantly exceeding what was available on the automotive market. We started building our team and looking for a shipyard where we could make our demonstrator come true. It was not an easy task, as we were looking at the ultimate design with carbon fiber used on all structural components and in as many places as possible.

Our time scale







Silent Straits Ltd. Continental office:Ul. Wróbla 6, 02-736 Warsaw, Poland

Advanced Electric Propulsion & Yachts