Sailing across the North Sea in a dinghy by Northbound

[Keith 66]

The LB ratio isnt really enough to exceed the hull speed limitation, her rowing boat inspired hull will make her fast & easily driven but the weight of the cruising gear she has to carry will make her unlikely to exceed hull speed to any high degree.
My current rowing boat is a stretched Cosine wherry, ostensibly similar but a much shallower hull, she is 17ft long & rows like a dream, she also has a 60sq ft balanced lugsail, with no dagger board. She can barely make to windward but off the wind on a reach or run is very quick, & will give a Laser a real run for its money in a breeze. To take her offshore like Northbounds boat would be suicide!
I think the hardest boat of all to design is a sail & oar boat that does both really well, most do one thing better than the other!
And yes it was John Seymour, long time since i read that book.

 

[dunedin]

Just wondering if the narrowness/beam might overcome the limitation of hull speed. ?

Any naval architect's out there ?

Narrow hull will lack form stability so difficult to generate much power under sail (unless large lump of lead 2m below waterline or twin trapezes) so generally slower than a boat which can generate more power and plane.

 

[Snowgoose-1]

Narrow hull will lack form stability so difficult to generate much power under sail (unless large lump of lead 2m below waterline or twin trapezes) so generally slower than a boat which can generate more power and plane.

I see
Like the old "lead mines" of old re AC.
I expect there is a reason why he picked such a narrow design. Hope he does a video about it.

 

[noelex]

The North Sea is the roughest water I have sailed in (although my wife feels the West Coast of Island in winter was worse). The trip from the Shetland Islands to Norway is only short and can be attempted within a favourable weather window, but still, it is a brave thing to do in the vessel featured.

Thanks for posting the video.

 

[boomerangben]

Just wondering if the narrowness/beam might overcome the limitation of hull speed. ?

Any naval architect's out there ?

Hull speed is not a hard barrier of course, just a sudden increase in power required for each increase in unit speed.

Where narrow vessels, or more specifically boats with a fine entry and streamlined stern, the size of bow and stern waves are smaller and therefore produce less resistance. I remember looking at the stern waves of a tradition fishing boat here in the outer Hebrides and marvelled at how little wake was being made, showing the importance of stern form.

Of course hull speed calculations are for smooth water. When you have a long passage with a following sea where the wave lengths are longer than the vessel and sufficiently steep, surfing becomes significant and of course the bow and stern waves are constantly being interfered with by wind waves. So down wind I can see why an average speed of greater than hull speed is not surprising. Going to windward would of course be slower, even with sufficient drive