Silennis S050

Who it suits

The S050 is Silennis’s step up from the S010 tender — a 7.50 m open electric boat for eight, in CE category C, still in development rather than on the water. At nearly twice the length and more than four times the weight of the 3.95 m S010, and rated for coastal water rather than sheltered lakes and canals, it is a quiet coastal day boat for people willing to wait for the yard’s first vessel of this size. Anyone who needs a boat this season should look elsewhere; anyone interested in where a small Spanish yard is heading has reason to watch it.

What the numbers mean

Silennis has now shared a full specification, and is explicit that the performance figures are estimates for a boat still in development, not measured results. The drive is the ESEA PD100 — 75 kW continuous at up to 500 V, 95 kg without its battery, and itself still being developed by ESEA Propulsion rather than by Silennis — on a 75 kWh battery. The yard estimates about 40 km/h (roughly 22 knots) flat out for around an hour, and a 10 km/h (5.4-knot) cruise held for close to eight hours, which works out at some 78 km — about 42 nautical miles — on a charge. Read those as intentions. It is the usual electric trade-off, and one Silennis argues for openly: the range lives at the cruise speed, not the top one, and a 75 kWh pack driving a 75 kW motor is roughly a one-hour battery at full throttle.

Caveats

The boat is in development and has no announced price, so treat this as a placeholder for a boat Silennis intends to build rather than one you can order today. The dimensions and the CE category are firm; the battery, speed and range are the builder’s own estimates and will move as the design and the still-unfinished PD100 motor settle toward production. When a production specification arrives, the two figures worth confirming are the usable capacity in kWh and the range at a stated cruising speed. José Alegría sent these specifications, and the first photograph, directly on 2026-08-11.