About this tender
The JT 21 is the size in Castoldi's range that opens up the upper end of the practical guest tender envelope. At 6.30m LOA and 2.60m beam, it carries twelve guests at coastal certification, runs to 34 knots top speed on a Yanmar 250 hp diesel coupled to a Castoldi Turbodrive 240 H.C.T. waterjet, and fits the standard tender garage envelope on motoryachts in the 60m bracket. This is the step where the Castoldi range moves from sub-six-metre tenders into proper big-yacht tender territory.
The Yanmar 4LV250 is a 250 mhp engine running at 3,800 rpm; combined with the larger Turbodrive 240 H.C.T. waterjet, the boat has meaningfully more performance reserve under load than the smaller 18 or 19. 155 litre fuel tank gives a working operating window for full-day shore-run programmes. Build standard is identical to the rest of the range: Kevlar and vinylester laminate, Italian factory construction, Hypalon Neoprene tubes.
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Highlights
The four details we'd point out first to a captain who hasn't seen one on the water yet.
The Yanmar 4LV at 250 mhp / 186 kW drives a Castoldi Turbodrive 240 H.C.T. waterjet. The larger drive is sized for the boat's weight and performance demands, with hydraulic clutch, movable grid for reverse and Clear-Duct unclogging. Top speed of 34 knots is competent for the size class with twelve guests aboard.
Cat C certification supports twelve passengers, and the deck layout genuinely works for the count. This is the size step where the Castoldi range starts to compete with stand-alone day boats for working capacity. For yachts hosting larger guest groups regularly, this is often the right answer over running two smaller tenders.
6.30m LOA and 2.60m beam matches the standard tender envelope on most motoryachts in the 55m to 70m bracket. Slightly longer and beamier than the 19, with proportionally more usable deck space. Confirm rigging point geometry against the mothership's lift specification before committing on a specific hull.
Same factory build standard as the rest of the Castoldi range. Yanmar parts and service available globally; the 4LV250 is widely fitted on commercial and leisure boats. Service intervals are predictable and crew-friendly, which matters on yachts running multi-year cruising programmes.
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The full specification
Specifications, prices, availability, and performance figures are supplied for guidance only and remain subject to confirmation by the yard, seller, broker, survey, contract, and final specification.
Questions, answered
Last call · Available
Castoldi · Albairate, Italy
Tell us about your yacht, your programme, and the missions 21 needs to handle. We come back within 48 hours with a written assessment - fit for the brief, lead time, and trade-offs against alternatives in the same band.
Prefer to talk? +44 (0) 77180 88055 · other ways to reach us
From the library
