International Cadet Dinghy

Synergy Marine Mk4 International Cadet


The first Synergy Marine Mk4 International Cadet hit the water at the end of 2014 and certainly turned a few heads with some of its neat design features and the quality of the construction.

Boats are available to order now. We can supply everything from a bare hull for upgrading an existing boat to a complete on the water, ready to race boat.  Contact us for further details or packages tailored to suit your requirements.

International Cadet Price List November 2016


Our Cadets are built using the latest composite technologies including Polyester resin infusion to produce the lightest, stiffest and strongest construction available. The hull and deck is constructed using PVC foam core with woven e-glass cloth used throughout. Hull and decks are resin infused under vacuum to consolidate and “pull” the resin through the glass fibres. We can accurately control the amount of resin required to wet-out the fibres and foam core. This method of construction provides a cleaner, safer working environment, reduces waste and enables us to build our boats consistently from one boat to the next.

Hull shape

The hull shape was developed in late 2010 to the new rules and produced our successful wooden boats, GBR 9876 “Zest” and GBR 9877 “No Regrets”. The design was computer modeled and a new plug was produced using CNC machined parts to provide the best shape possible. We then built the new mould tooling along with the new Mk4 Deck mould. Based on previous World and National Championship winning designs, we strongly believe that we have the best all-round Cadet hull-shape available.

Shroud attachments

A common problem with Mk4 Cadets is the use of U-Bolts to attach the shrouds. To alleviate this we are using shroud plates that are fitted to the hull. This ensures the rig loads a distributed through the hull rather than the hull deck join which can flex and crack over time. We also use a quality bow fitting for the same reason. Sailors will now find that they maintain their rig tension over a whole day’s sailing.

Buoyancy Hatches

We’ve found over the years that one of the main places for Cadet’s to fail their buoyancy test is through the buoyancy hatches. This causes the boats to fail their test but also take on weight. To alleviate this, and also a safety measure, we have moved the forward tank hatches to the fit within the spinnaker bag recesses. Moving them higher means they are less likely to be below the water level after capsizes. In addition it is also possible to bolt, rather than screw, the fittings on the foredeck and bulkhead which previously wasn’t possible.

Grab Rail

We have introduced a moulded in grab rail which looks neat but also removes another fitting which is otherwise a known point for buoyancy leaks.

Centreboard Case

We have refined the centreboard case capping with a sloped downwards thwart to allow more space for the crew. In light winds they can get their weight lower and in breezy conditions it’s very easy to move aft.

The spinnaker halyard now neatly passes through the centreboard case providing a more natural location for the cleat.


For the crew the toe straps are in the traditional location, with the added benefit of built in cleats for adjustment.

For the helms toe straps the main anchor point has been moved forward to provide a more stable hiking position. Longer toe straps mean that it is harder to hold your position fore-aft can be very energy sapping, particularly in windy and wavy conditions. When it’s very windy downwind there’s a short a “pussy strap” at the back of the boat for the helms to really lock themselves in for the ride!

Side decks

The side decks have a neatly moulded non-slip which won’t damage clothing but will stop the crew from sliding and wasting energy. It also means that the use of pro-grip will no longer be required keeping your boat looking very neat and tidy!

Colour choice

At Synergy Marine we believe life is too short to be boring. So many new boats are shades of grey so we are encouraging colour – be it splashes of colour on the centreboard case, floor or hull. Sailing should be colourful like many other emerging sports – skiing, cycling, motorsports and other watersports.

Hulls will be spray painted rather than gelcoat. This enable us to offer a wider range of colours and makes repairs significantly easier. Those all-to-common Cadet bow repairs can easily be made to look as good as new, without patchwork gelcoat repairs.

The other advantage is that its much easier to change the colour of the hull for future generations of Cadet sailor, perhaps another second-hand value adding feature!

Research & Development

IMG_2236P1060772At the end of 2010 Matt White approached Synergy Marine’s Simon Cox, about building a new International Cadet dinghy for daughter, Emma, in her last year of Cadet sailing. Matt, a former Cadet and successful sailor himself had a good idea of what was required to produce a fast boat. Simon, with over 25 years sailing experience, brought new ideas and construction methods to the project to make the new wooden Cadet a reality.

The first priority for the new boat was that it should perform well across all wind and sea conditions. Secondly the boat should be optimized for children in the last years of their Cadet sailing career.

Opinions and advice was sought from current and former successful Cadet sailors and respected Cadet coaches throughout the project. This advice helped make the decision to build the boat to the Mark II design with wider side decks.

Once the design parameters had been determined, the hull was developed by computer to ensure a fair and symmetric hull shape. The frame for the mould was produced from the computer model using Synergy Marine’s CNC router which is normally used for producing high quality dinghy foils.

The resulting design is a hull that has moderate rocker, is close to minimum width particularly in the forward sections utilising the December 2010 rule changes and with a few other design tweaks for improved structural stiffness.

Current Price List

Current introductory pricing is available until 31st December 2014.

International Cadet Price List December 2014