The next question was which design. 2 months were spent researching as many designs of around 40 ft (the minimum for a comfortable safe blue water boat ?) as I could find. Had settled on Derek Kelsalls KSS-40 when my brother elected to join the project so we moved one size up to his KSS-46. The reasons behind this choice (in no particular order) are:
- Dereks designs look good, the style appeals to me
- Fast and seaworthy hull shape
- The construction method, unlike just about every other design on the market the hull panels are made on a flat table and then bent to shape. This should mean less labour, less sanding, less fumes, less dust, better strength/weight ratio, good exterior finish.
The disadvantages (and at this stage it is difficult to tell if they will prove to be serious issues or not) are that the method is relatively new and in particular there is not much experience locally of using resin infusion.
Modifications: The KSS-46 is more like a 42 ft catamaran on 46 ft hulls. We wanted to make a few modifications and fortunately Derek was happy to oblige:
We wanted to increase the all up weight from 6.5t to 7.5t to allow for extended cruising gear, this was done by increasing the rocker on the hulls.
The bow was brought to nearer vertical, so increasing the waterline length.
The stern was lengthened by 2 ft above the waterline, the idea being that as speed and with the stern dropping the hull form drag will still be efficient.
Raising the bridge by 15cm to reduce slamming.
Increasing the sail area by 15% to carry the extra weight and adding a bowsprit and screecher.
Redesigning the cockpit area and interior layout.
The picture shows the redrawn profile with extended stern and modified bow. Increasing the bridge clearance had more significant implications to the whole of the build - the above sheer panel (the long thin one shown dark on the drawing) needed to be made higher to keep sufficient headroom, so effectively every panel in the boat is changed from the original plans and would have to be measured to size as construction proceeded. Derek would have been been willing to redo the drawings but I was happy to work these out as work progressed. One disadvantage of taking this approach was that panels needed to be made as the boat progressed and could not be sized from the plans. It did leave me more in control of developing the design as the hulls came together.