Williams vs Castoldi: comparison 2026
We pit Williams Jet Tenders against Castoldi with the usual script: what each builds, with which materials, in which price range and which boater each makes sense for.
Williams 
Castoldi Comparison table
| Williams | Castoldi | |
|---|---|---|
| Country | United Kingdom | Italy |
| Founded | 2004 | 1962 |
| Specialty | Jet tenders (waterjet propulsion, no propeller) for large yachts | Jet tenders (Jet Tender line) with in-house waterjet drives |
| Hull materials | Fibreglass (GRP) | Fibreglass |
| Tubes | Hypalon (CSM) | Hypalon (CSM) |
| Size range | 2.8 – 6.25 m | 4.3 – 8.6 m |
| Price level | €€€€€ — Premium — from ~€30,000 for the smallest model | €€€€€ — Premium |
| Ideal for | Owners of yachts with a garage who want a sporty, safe, luxury tender | Yachts and superyachts wanting a robust jet tender with industrial pedigree |
Williams, in short
Williams Jet Tenders, founded in Oxfordshire (UK) in 2004, dominates the jet tender niche: tenders propelled by waterjet instead of a propeller. That makes them ideal for a yacht garage (minimal draft, contained length) and for swim areas (no exposed propeller). Standard or optional equipment at yards like Sunseeker, Princess and Fairline. Quality and price at the top of the market.
Strengths
- Jet propulsion: no propeller, maximum safety for swimmers and towed sports
- Minimal draft and compact size for yacht garages
- Luxury finish and sporty performance (Minijet, Turbojet, Sportjet, Dieseljet lines)
- De facto standard on 15 m+ yachts with a garage
Things to consider
- Premium purchase and maintenance costs
- The jet requires specialist servicing
- Less efficient than a propeller at low speed
Castoldi, in short
Castoldi is a historic Italian manufacturer (Abbiategrasso, since 1962) famous for building its own waterjet drives. Its Jet Tenders are the industrial, robust alternative to Williams: highly valued on superyachts and also in professional and military versions. Maximum hull-drive integration and built to last decades.
Strengths
- Has built its own waterjet drives since the 1960s: total integration
- Robust construction also aimed at professional and military use
- No propeller: safe in swim areas with minimal draft
- Established prestige in the superyacht market
Things to consider
- Premium price
- Specialist jet maintenance
- Range starts at 4.3 m: no compact option
Our verdict
Choose Williams if you fit its profile: owners of yachts with a garage who want a sporty, safe, luxury tender. Choose Castoldi if the opposite applies: yachts and superyachts wanting a robust jet tender with industrial pedigree. And if budget rules, Williams starts with a price advantage — though it always pays to compare specific models at equivalent specification.
Our practical tip: before deciding between these two, also get a price for an equivalent Navisoul model. With Hypalon available across the range and yard customisation, it often wins the comparison without the brand premium.
Frequently asked questions
Which is better, Williams or Castoldi?
There's no single answer: it depends on use. Williams stands out for jet propulsion: no propeller, maximum safety for swimmers and towed sports, while Castoldi stands out for has built its own waterjet drives since the 1960s: total integration. On price, Williams is usually the more accessible of the two.
Which is cheaper, Williams or Castoldi?
In general Williams sits at a lower price level (premium — from ~€30,000 for the smallest model) than Castoldi (premium). The final price always depends on the specific model and configuration.
Are there alternatives to Williams and Castoldi?
Yes. At dinguis.com we sell the Navisoul range (Caral Marine) and advise on any boat and brand on the market, as well as analysing them in our comparisons.
We help you decide
Tell us your boat, where you'll stow the tender and your budget, and we'll tell you which specific Williams, Castoldi or Navisoul model fits best — with numbers, not fluff.
- A comparison tailored to your case
- Reply within 24 working hours
- No obligation
Williams, Castoldi or another? We can help
We reply within 24 working hours with price, delivery time and customisation options.