Hi Rick,

Waterlines are well and good, but as an old time boat painter they really are only the starting point.

Normal gloss marine paints are fine for a week of immersion without any problems at all. If the right process is followed they won’t suddenly fall off or anything dramatic. Towards the end of the week they will start to get slime – which is not hard to remove, but it establishes a ecosystem for coral worm, weed, barnacles to survive in.

So if much more than a week without being used then will need an antifoul paint. Be aware there are many types … you need one that is suitable for trailerable boats which does not deteriorate out of the water for extended periods.

Using a boat regularly is a great way of keeping growth away. Also if the boat dries out (eg tide goes out or pulled up on a beach) for a couple of hours a day then it will be OK for much longer.

When empty with mast up the Oz Goose will sit in the water bow down. So the paint needs to go up to the front end of the bottom. if there is ever gear left in the hull or the mast is left out the bottom will be wet its full length from wave splashing.

So I recommend that the bottom paint go from the bottom corner of the bow transom to the bottom corner of the stern transom.

This is not unusual. As if you use the waterline itself to paint a yacht – the yacht will sit bow down on the mooring because of no weight in the cockpit and the weight of the mooring chain. But sit stern down or on its lines when sailing. So the normal thing is to have the paint higher than the waterline at the front by a few inches and only higher than the waterline at the back by half that. BUT if the boat has flat areas where the water will splash around continuously then that needs to be protected too. Often the top edge of the bottom paint is not straight, but a subtle curve rising in the ends a bit.

MIK

Hi Tony,

The information you need is on this page. Interestingly (and a little bit obviously when you really think about it) the outer diameters need to be pretty close to the wooden values.

The full information is on our sister site.
https://www.opengoose.com/building-a-goose/materials/substituting-aluminium-spars-on-the-oz-goose-sail-boat/

Best Regards
MIK

I’m half-way through the hull build – & enjoying your plans!

Do you have dimensions for an aluminium mast for an Oz Goose – that has proved to be a suitable match for a Realy Simple Sail from Duckworths?

Would 40mm x 1.6 do the job – or 40mm x 2mm?
Cheers, & sincerely,
Tony.

Hi Chris,

Why do you want to change it?

I’m guessing the hull height is something to do with the plywood widths you have available?.

Michael

Best wishes
Michael