Norwalk Island Sharpies NIS 31

This is a boat that I would like to build. The NIS 31 (designed by Bruce Kirby of Laser fame) is fast, it’s larger than mine (especiallt when stretched to 35 feet), it has shoal draft (1’6″ / 46 cm with board up, 6’6″ / 2 m with board down) and it looks good! It should be among the easiest boats to build for its size and I am currently waiting for the study plans to arrive.

Here’s the brochure in PDF format.

NIS 31 Mudlark

NIS 31 interior layout (I would change this)

Drawbacks

There are a few drawbacks with the design. First of all, being a centreboarder with all it’s advantages, it also has a few disadvantages. It has a centreboard trunk right in the middle of the living space. The centreboard trunk is also something that can potentially get clogged up by mud and/or rocks while beaching. The other factor is speed. The sharpies are known to be fast, and running off the wind it’s possible to plane/surf and reach speeds between 15-20 knots (story of its little sister, the NIS23, sailing across Bass Strait, running at 17.5 knots). That’s fast for a monohull! The downside is that this can be dangerous. My current boat (Fingal 27) has a “half-full” keel that helps with keeping the boat on track, while the NIS31 which only has a centreboard. It’s usually kept raised when running and this might increase the risk of broaching. This combined with the high speed can make offshore passages a bit risky and brisky! On the other hand it makes coastal sailing so much more enjoyable.

There are also those that argue that having shoal draft will let the boat “slide” over a breaking wave, instead of tripping on its keel. I’ve also had a storm tactic idea, which is to lie ahull with the centerboard up and warps out from the side at deck-level, which in theory might keep the boat from heeling over excessively.

NIS 31 Talisman

The right boat

I would really like to build my own boat though. In fact I dream about it almost every day. I have so many small things I’d like to change about my current one and even if it would be enough, it would probably be less work (at least not much more) and more fulfilling in the long run to do everything my way from scratch. I would also save a considerable amount of both time and money if I re-used the rigging, lead, winches, ground tackle, rope, blocks, (wooden) interior bits and pieces from my old boat. I made a quick calculation that I could build the boat for between 10-15.000€, depending on the materials used.

NIS31 Talisman at Great Keppel Island

Questions

One minor detail is the rudder. Because it lifts up, both a servo pendulum and a trim-tab self-steering gear will be somewhat tricky to implement. This can likely be solved in different ways though.

The Hebridean wind vane servo pendulum self-steering (the boat in the picture is not a NIS)

By the way, speaking of self-steering, I’m considering buying/building the Hebridean, or an own design based off that one. It looks very smart and is a lot cheaper than the competitors (that I’m not even considering).

A NIS 31 beached

Another issue is where to place a rigid dinghy. It has a fairly large cabin with very little deck space and I would preferably not stowe the dinghy on the cabin top as I’d like to keep weight above and windage to a minimum. One solution would be to shorten the cabin and thus create a larger foredeck. On the other hand, having shoal draft, the boat itself can be used as a dinghy.

Rig

I would most likely rig it with a soft wing sail (loosely based on this design by David Tyler). I am currently designing one for my current boat and will use it as a prototype. If successful I should be able to simply transfer it over to the NIS31/NIS35 and add a mizzen, making it a ketch rig. David Tyler has successfully cruised 40.000 miles with his wing sail rig.

David Tyler’s Tystie, with its wing sail ketch rig

The other alternative would be a junk rig. I prefer to keep things as simple and low tech as possible. I even considered going engineless, but with the NIS31 having a very practical outboard well I am definitely getting a small engine for it. The easily handled soft wing sail rig will keep me from not using it very often. I rarely even use my engine now when I have one, instead I usually sail to and from the wharf.

Yet another NIS31