When i was out in my kayak I saw a swan. She might have the same displacement lenght ratio as my boat the YRVIND TEN.

I said to myself.

Back home I got some numbers. A swans weight is 12 to 15 kilos, her designed waterline lenght is about 2 feet that gives her a displacement lenght ratio of 1500 for 12 kilos.

Now YRVIND TEN got a ten feet waterline her estimated weight is 1.5 tons. That gives her the same displacement lenght ratio of 1500. Now a swan is quite a fast mover. Scale her up 5 times and her hull speed increases by the square root of the scale or 2,236. The hull speed of a swan is 1,35 times the square root of two, her waterline lenght. That is 1.909.    2.236×1.909=4.269 knots. That speed will give me 100 miles a day. That is in ideal conditions. If I get half 50 miles a day I bee happy.

An other thing. I did climb the mast to inspect the damage done by the bridge I hit trailing her home from Stockholm. The mast was hit about 20 cm / 8 inches from the top. It was a big bang but the solidly built mast is still in good health.

Regards Yrvind.