The next problem was both Turnigy ESCs burnt out! Not simultaneously, but in quick succession. Have no idea why. They were well protected by fuses and generously sized for the motors and screws.
Anyway, HobbyKing refunded the purchase. Obtained two more ESCs, but this time from Banggood. Had several premature Turnigy failures last year; time to try something else.
The Banggood ones worked straight out of the box. They do not require programming and operate simply in Fwds or reverse; no beeps, punch mode, throttle setting or other complications.
Just as well as my Turnigy ESC programming card had, by now, also failed!
These ESCs are basic and do not have a low voltage alarm or cut-off. When using LI-Po batteries it is essential one be added to protect LiPo cells from inadvertent full discharge damage.
Once these ESCs were installed was immediately impressed at the improvement in control. They could be fully modulated from the Tx lever. The Turnigy ones were much coarser and the hull could not be safely docked, it can now.
The drivetrain trials and tribulations were resolved, the model sailed well throughout several runs. It is not as fast as the Brave Borderer, but with only two screws it is lighter and easier to control. It also planes easily.
Although the original vessel had twin screws that rotated in the same direction, decided to cheat and install contra-rotating screws. Experience with the Brave B. steering shows it is sensitive and felt this might make the model more predictable and also reduce any “digging in” tendency on turns.
Quite enjoy running a bare hull as it is not susceptible to minor damage. All marks can be cleaned off during the build programme.
Parked the model for the onset of the winter, when will complete it. The pictures show the final tests in Hamilton Harbour.

Purchased, about this time last year, a glass fibre hull from MTBHulls. Have used their products before and been very pleased with them. Prefer to use GF hulls on these faster models are they are so robust.
Proceeded through the Spring and Summer to fit the twin-screw brushless drivetrain, so it could be thoroughly tested before the deck was installed. Have found, through bitter experience, this is the easiest way to commission a brushless motor installation. It allows much better access to adjust or replace components. My caution proved well founded!
Obviously, running on open water without a deck runs the risk of the model filling and sinking. To address this, fitted inside the hull old plastic water bottles and some air-filled sealed plastic bags usually used for protecting fragile shipments. Had earlier calculated the buoyancy given by these items, so it did exceed the hull weight.
On the first runs, found the Turnigy water cooled brushless motors leaked water heavily. Possibly exacerbated by the pump circulated water-cooling system. This is evidently a well-known problem and even described on YouTube!
Fortunately, easily cured by applying sealant to the area around where the wires emerge. Access was too limited to do this in situ, so removal and bench repair was the easiest approach
To be continued

Decided to build a model of an RAF Rescue and Target Towing launch (RTTL) as my next project.
Spent much of the winter and Covid lockdown period working on this 1:24 scale model. As the build closely follows my earlier Brave Borderer project, will only describe significant differences or areas of interest.
The original vessel was designed and built by Vosper in the U.K. for the Royal Air Force in the early 1950s.This Mk 2 RTTL version, was eventually powered by 2 x Rolls-Royce Sea Griffon engines (the Griffon, although a similar style engine to the Merlin, was not a development of it).
The one I chose to model was 2762E. This originally had an aluminium plated hull and was built for experimental purposes to evaluate this feature. The “E” in the pennant number depicts “Experimental”. The R.A.F then realized it already had a 2762 vessel, one captured from the Germans! She was renumbered as 2772E.
In service it was found the aluminium sheathing corroded quickly in the salt water. She was then resheathed in double planked mahogany, just like her sisters. The pennant number then also became plain 2772.
In the original guise this hull was both lighter and had a smoother surface finish than usual, so was capable of over 50 knots. The standard vessel topped out at around 47 knots.
Planned to use a glass fibre hull. The smoother surface of GF would more closely replicate this particular vessel and would thus give an ideal opportunity to capture a unique period in her life. Also wanted to capture a version with the low engine room hatch, although 2772 was later converted to the raised glazed version.