About WattsCraft

WattsCraft is a small business based in Otago, New Zealand. We primarily design & build small aluminium boats. We also have tools and knowledge to tackle other engineering, metalwork & industrial design projects.

WattsCraft use modern design tools & processes. We outsource certain fabrication processes such as CNC cutting as required to a range of specialist companies, this gives us the flexibility to use the best process for the job. 

  • CAD Design

  • Welding - TIG, MIG, ARC (All materials)

  • CNC cutting - Router, laser, water-jet, turret punch, etc

  • Forming - Press brake, rolling, tube bending

  • CNC machining/milling

WattsCraft boat design

WattsCraft specialises in designing high performance river jet boats. We pay careful attention to several attributes which are particularity important in small boats.

Good weight distribution is essential to ensure performance & increase stability when running aground. Assuming all other factors remain the same, as a boat becomes narrower its static stability is reduced. WattsCraft designs "add" stability by:

  • Using a shallow dead-rise - this allows the centre of gravity to be lower relative to the chines of the boat. This makes the boat harder to roll over.

  • Mounting heavy items low & at the rear of the boat. This keeps the centre of gravity as low as possible. It also helps to keep the boat tracking straight when running aground. Excessive weight in the front of the boat can cause plowing & bow-steer in water & on gravel.

  • Using low seating near the centre (longitudinal) of the boat. As passengers are a larger proportion of the total weight having low seats is much more important to stability in smaller boats. It also helps when ducking willow branches. Avoiding having seating to far forward is also important to avoid excessive weight in the front.

  • Hull design. Small boats typically carry more weight further forward. We use a constant dead-rise design to provide lift in the bow area & ensure a flat stable ride at high speed.

Having positive predictable handling in a river full of obstacles is important and a small nimble boat is a big advantage in your typical NZ river. WattsCraft have a few priorities when it comes to handling.

  • No unexpected spins. We design our hulls to avoid bow steer (oversteering). Our constant shallow dead-rise aft section resists porpoising, tracks straight and gives predictable cornering. A moderate bow entry allows for positive steering with standard jetski deflector nozzles & cuts through little chop with a dry ride.

  • The constant dead-rise hull sits flat as speed increases & never rides bow down. Cornering remains constant & inspires confidence at any speed.


WattsCraft hulls are CAD designed, CNC router cut and CNC folded. 5083 grade Alcoa marine aluminium plate is used throughout. 

The hull is reinforced by folded plate longitudinal stringers. The topsides are a strong monocoque structure with large folded box gunnels which require no framing for strength. The windscreen is strong & high enough to hide behind should a tree branch drop unannounced into your path.


WattsCraft designed finger throttles are a key design feature in our small boats. We find it much easier to maintain complete control compared to a foot throttle, even when bouncing down rapids or standing to drive. SSS Engineering do great foot throttles if you prefer.

We use cable & pulley steering from SSS. This is typically found on full sized jet boats & marathon race boats! 

SSS reverse & trim controls are also used.

ASPCNC cast intakes & river grills are used. These are by far the most advanced intake/grill system available for adapting jetski pumps into river jet boats.


Photo: Nay Hauss

Photo: Nay Hauss

Henry Wadworth-Watts (Owner)


  • ME (Environmental engineering)

  • BE(hons) Chemical & Process Enginnering


  • Boat & industrial design

  • Architectural metalwork

  • Environmental engineering

  • Chemical & Process engineering