Concept to Launch
Launch
There was a mark on the side of the hull where Phil wanted the boat to float – and it did.
Towing the boat to the marina, the economy light on the RAM went on – indicating that the aerodynamics were pretty good.
Suzuki had supplied propellers based on their speed estimates for the boat – the 19.5” were a tad small with the boat redlining very quickly.
Graham from Suzuki NZ came down and the 25” propellers were fitted, two runs later 52 knots and then 54, so 101 km per hour through a 25 knot southerly.
Whilst the propeller could go bigger the decision was made to stick here – the boat will normally be fully loaded and it’s about comfort and soft ride.
Towing
Initially a Ram Laramie was purchased through Brent Boddy Prestige – with the boat and trailer weighing in at 4570 kg there was a need for a sound towing solution , whilst also a comfortable ride for those long distance road trips.
Not long before Seahawk was launched a new Ram came on the market and with a far superior towing capacity, the Laramie was traded in.
The new 2500 Dodge Ram rated at 6.9T towing capacity with torque generated by a Cummins diesel had enough power to make Phil have to check in the mirror that there was a boat on board.
The increased towing capacity made the model swap a no brainer providing far better on road stability, added comfort and increased safety.
The Future
The boat has had strong interest from a number of marine businesses who are looking at replacement or additional vessels – it is well suited to serious fishermen, game fishing and could be modified for cray as well.
There could also be a role within marine rescue , for coastguard, police or airports with tailored design on the base boat available.
The learnings from this first build will allow a faster more efficient build process and Phil is sure that the first order will not be far away.
Design
Phil Morris built the Eliminator boat 26 years ago and the boat was seen widely throughout the North Island and top of the South.
His many hours spent refining and enjoying the Eliminator and his 40+ years of experience working on a wide range of marine craft led Phil to believe that boat design could be done different – and better.
The Eliminator was a tri-hull wave piercer coming in at 7.6 m – handled well into a head sea and was stable at rest.
The traditional monohull design has been recreated in every shape and form and whilst the materials used to build the monohull have moved with time there have been no real improvements on the hull design. The US navy were using advanced multi hull designs – was this the way to go?
What were the design elements that were important?
- Fast
- Efficient
- A working recreational fishing boat not a cruiser
- Ability to handle the rough
- Both the design and the visual perspectives were important
- Form and function needed to be aligned.
- Ride softly.
- Maintain high average speeds.
- Be very stable at rest.
The basic design was sketched on large pieces of paper on the kitchen table over the course of a year in Phil’s spare time – Phil could ‘see’ the boat in his head and used the sketching to recreate and refine this vision into design plans. The original sketches are discarded in the corner of the office.
These sketches were then handed to SolidWorks guru ‘Sam’ who transcribed all the sketches into the SolidWorks design program. There were a dozen or more iterations of the original design – refining and fine tuning to ensure that technically the boat was looking ok. From the sketches first appearing on SolidWorks through to the design being ready for construction took approximately six months.
Building the Hull
Using SolidWorks and the CNC router the basic hull was cut out – interestingly the basic design for the hull did not change from those original sketches. The team pressed the main tunnel sections – with extreme accuracy required for the multiple folds. Then the ribs and the bulkhead were formed up – using a jig on the workshop floor with aluminium strops holding it all together. As the basic form took shape the hundreds of individual pieces needed to be aligned until three months later the basic hull was finished. The cabin design initially sketched out just didn’t work – it needed to be highly functional and visually appealing with key elements being aerodynamic function minimising wind drag and maximising cabin space.
Composite Cabin design
A local craftsman who could build the cabin in carbon fibre solved many of the design challenges for Seahawk being that the cabin would be strong, lightweight and holding its complex unique shape.
The cabin top was sketched out for Sam, to then draft into SolidWorks – with Sam’s skills , less than three hours later the first design was generated and then following revisions it was cut out in ply using the CNC router. The ply profiles made the rib structure for the cabin top. SolidWorks allowed a ‘stickman’ to simulate walking around the cabin top design so that those taller members of the crew weren’t going to bash their heads. The ply ribs were then connected and lifted off in one piece – the composite craftsman then clad the frame with 40mm wide pieces of timber and then the carbon frame was layered over that, smoothed and then vacuum packed and infused. Once the top was back it was dry fitted allowing all of the internal design, dash and instrument panels to be scribed into place. Then it was off to the painters. After the cabin top and hull were painted , they were fitted permanently together.
The final cabin weighs in at an astonishing 63 kg.
Wings
Something that makes the Seahawk stand out are the unique wings that appear on top of the cabin – they really do make the boat fly with the design concept being to make use of the wind coming over the top of the cabin to generate lift.
There will be some drivers in Wellington who watched in amazement as the Morris Metal trucks drove up and down the motorway with the wings attached to the truck deck modelling the lift generated by the wings. Boeing airplane modelling indicated lift of 490 kg at 100km per hour. This unique design lightens and stabilises the boat with the lift being on top of the cabin.
The actuator can be manually altered using a push button to change attitude of the wing – and it looks great.
The Trailer
One learning from when the Eliminator was built – Build the trailer first so that you can move the boat framework around.
Sketched initially on paper and then transferred to DesignWorks by Sam. The trailer is 11.7m long. The side pieces are cut from 10mm plate and act as the main trailer chassis as well as the wheel arch structure. The trailer weighs in at 1400 kg.
Details
Twin DF 350 Suzuki’s were chosen after an exhaustive search based on the new dura prop system and on fuel economy. They took several months to arrive in the country and the boat was nearly ready for them when they arrived pre- Christmas.
Once the motors were chosen, the hull was designed around them – wooden cutouts were made early in the build process so that the motors could be positioned in the correct place – their very narrow power heads could draught in behind the sponsons.
KP Marine were responsible for sourcing and then fitting the motors.
- A fusion signature series sound system was fitted to lull the fish into submission
- Koden was used to supply and install the commercial fish finding equipment – simple to use and graphics were easy to decipher for fisherman.
- All the standard communication devices have been fitted with USB ports scattered through the boat as well.
- LED lights have been fitted under the gunnel and soften at night so as not to be too harsh.
- A 6000 lumen 360-degree spotlight on the roof works off a handheld remote.
The Cabin: it’s a fishing boat not a luxury launch but there has been a lot of thought go into the design.
- Room for five people
- 115 L chilly bins which clip into place and double as seating and storage.
- Generous berth down below for a snooze with porthole windows for fresh air, carpet, led lighting and storage nooks.
- The forward bulkhead contains all the anchor warp and chain capstan mounted inside to not disrupt airflow – there should be no need to go forward into this area.
www.kpmarine.co.nz / www.suzukimarine.co.nz/find-a-dealer
SJ Seahawk Team
This build was a team effort – the Morris Metal Team of Phil, Mark, John, Sam, Aaron and Alex were all involved in the build process.. The build was supported by an amazing group of suppliers who went above and beyond to help build the SJ Seahawk
