Contacted the Glass fibre supplier, who offered to mould a lighter hull, at around 100g. Ordered it and arrived promptly. Nice and light at 100g, but somewhat flexible. A thorough dimensional check showed a slight twist in the forepart.

Have found that a gentle application of heat, by electric heat gun, to GF will allow the shape to be worked and adjusted. Warmed the hull and twisted in the opposite direction to straighten it. This worked and the hull became true.
Was concerned that the twist might reappear over the months before can start the build, thus added a light bulkhead and bulwark stringers to hold in position. So far this has worked.
Now trimmed the bulwarks to shape and filled a small strip around their top edges to glue the deck down too.

Concerns over weight encouraged me to weigh every component physically. Biggest challenge came from the choice of brushless motors. An ESC is needed for each one. These are significantly the heaviest items, but have the best performance.
Surveyed scores of ECSs and motors trying to arrive at the lightest combination, but with best performance. Also had to compromise and omit an independent BEC power system to save weight, used the integral ESC one.
The propellors at this size are only available in plastic. Also had to make the shafts out of brass rod with an aluminium tube as could not readily find the more traditional stainless shaft with brass tube in the necessary sizes. Should also be nominally lighter,

Total weight of all these components, along with hull and bulkhead came to 270g.
This is rather less that the 450g target. Have a test 150g battery, which when installed, brings the model to the waterline. If this works well, hope to find a lighter battery with a similar capacity. Does confirm the 450g weight target appropriate.

Just hope the paint, glues and superstructure weight can be contained in the difference!

After the end of the war the Royal Navy decided to move from gasoline powered fast launches to diesel, to reduce fire risks.
The first major diesel powered boat class was the Dark, introduced in the mid1950s. These were powered by two Napier Deltic horizontally opposed, triangular layout two stroke diesels.

Shortly after this class was introduced it was determined the role of the Fast Patrol boat had been superseded by helicopters and aircraft. The Fast Patrol vessels were then gradually withdrawn.
To retain competence in the use of fast vessels, the RN commissioned three fast training boats (FTBs), the Scimitar class. This was the last high speed RN class of the era.
They were similar to the Brave in many ways. Both were built by Vosper and the lineage is evident. Rather than three Proteus gas turbines, they only had two, although with CODOG diesel units for slow speed operation. They were unarmed and designed to give R.N. crews experience in fast, coastal patrol boats.
The vessels could be armed and converted to three Proteus turbines if circumstances changed.

Our COVID lock-down hastened progress on my Dark class project, so have been trying to find another build for the coming winter. Have decided to model fast patrol type vessels for the time being. They are great fun on the water.

Would have liked to build a Scimitar Class FTB in around 1:32 scale, again using a GF hull from MTB Hulls, but that scale was not in their range. A GF hull is light and robust, well suited to these vessels. MTBHulls did offer a 1:72 scale hull, but that worked out around 16.5” long. Thought it would be too small for a working scale model.

Was in touch with a modeller in Australia who has made similar models. He also pointed out the number of successful “plastic magic” conversions of kits that are around this size. Obviously, it is achievable. Would give an unexpected change as the larger scale would have been similar to my recent Brave Borderer and R.A.F. RTTL projects.
The biggest challenge will be to keep the weight down to around 450g.

Looked an interesting and challenging project and at such a small scale one with plenty of potential for failure.