Waterjet History

HamiltonJet Waterjet History

In the early 1950s, when Sir William Hamilton began experimenting with marine jets, he followed the lead of the most successful invention to date, the American Hanley Hydrojet. Using a round centrifugal water pump that drew in the water and expelled it through a steer able nozzle under the boat, he was able to achieve an encouraging but unspectacular speed of 11 mile per hour.
Click here for Installation and Service Manuals for many of these older waterjet models.


A slight modification to expel the jet stream above the waterline proved the turning point in marine jet propulsion, increasing speed to 17mph and eliminating all underwater appendages. Waterjet propulsion was at last truly successful and the Hamilton Waterjet was born.
This first type of unit was named “Quinnat” and consisted of a vertical shaft centrifugal unit, driven through a right angle gearbox.


The first batch of “Rainbow” jet units were produced. A small direct drive centrifugal type of unit, the Rainbow gave a good performance in a suitable light craft, without the noise of a gearbox. About 100 were manufactured and marketed in New Zealand.


This year saw the birth of the “Chinook” unit. A twin impeller axial-flowturbine, the Chinook was far more efficient with its straight-throughflow and two-stage pressure build up. Following this came the three-stage Chinook unit which increased performance further.


The “Colorado” series of jet units was a completely new, greatly simplified design which halved the cost of the unit. This series was developed into a full range of one, two and three stage units driving a widerange of boats from river-runabouts to off-shore racing craft.
Click here to reference parts drawings and manuals for Colorado Junior and Explorer jet units…


This year saw the introduction of the “Work Jets” – larger, heavy duty units designed for diesel commercial vessels, large launches etc. The WorkJets were the forerunners to today’s Hamilton HM Series of larger waterjets.


The 750 series of jet units evolved a standardised method of installation in hulls, regardless of the number of stages. This gave more cockpit space in the boat and employed modern controls and engines. Preceeded by the 740 jet unit (Colorado pump with 750 intake) and followed by 770 series jet units


First ‘commercial’ waterjet, Model 1031, introduced. Large diameter, single stage unit.


400 Series waterjets are introduced. These are four craft up to 30 metres long.


Split duct deflector developed for 1031 jets and then introduced on all Hamilton Waterjets. The split duct design increases astern thrust by directing the jet stream down and to the sides of the boat transom to avoid recycling and increase steering responsiveness.


HM Series waterjets, for craft up to 60 metres, is introduced.


HS Series waterjets, for 50-65 knot craft, is introduced. These were multi-stage waterjet units designed for high-speed light commercial craft with power inputs up to 1,600kW.


New jet models introduced to fill holes in Hamilton’s waterjet range – HJ241, HJ321, HM461.
Existing models further developed with more efficient intake and screen designs, 0 and 5 degree intake block options, and improved anti-fouling/anti-corrosion protection.
Largest Hamilton Jet model waterjets developed – HM651, HM721, HM811.


Turbo impeller developed along with HJ212 model to replace the multi-stage 773 unit in trailerable boats. The Turbo impeller improves jet performance in aerated water conditions.


Control Monitoring Unit (CMU) developed as a fully electronic jet and engine control system for larger waterjets.


JT Steering system introduced. Nozzle design minimises thrust loss when steering to improve steering control and course-keeping efficiency.


MECS (Modular Electronic Control System) supersedes CMU for electronic control.


HJ403 waterjet unit superceeds HJ391 in model range. New model features improved design for greater efficiency, ease of installation and lower maintenance, as well as a new ahead/astern control systems.
Dynamic Positioning interface for MECS developed. This allows MECS to interface with a ship’s DP system to improve station-holding ability and general safety around oil-rigs.


VoyageData Recorder interface for MECS developed. Sends waterjet control history to a vessels VDR (similar to an aircraft’s “black box”) for future reference in the event of an accident. Primarily used on fast passenger ferries.


Introduction of the blueARROW control system sees a new era in waterjet control. More compact and reliable, and easier to install and maintain, than MECS, blueARROW brings electronic controls to smaller waterjet models HJ292, HJ322,HJ364 and HJ403.


Enter the MouseBoat – the first installment of next generation waterjet control devices from HamiltonJet. Incredibly intuitive and simple to use, the MouseBoat ensure anyone can harness the full manoeuvring capabilities of waterjets.


The first HT1000 waterjets are manufactured, increasing HamiltonJet’s size range above the HM811.


HT810 and HT900 Range successfully launched to include HT810 and HT900.


HamiltonJet celebrates 75th year Anniversary