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fast sailing
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Last post by
MazeRat7,
There are 3 ways you can go faster then 'hull speed' that I can think of.
1 - sailing in a following sea where the waves are big enough to surf. You will experience an increase in speed as the boat surfs each wave.
2 - sailing with a current. In the East River and other tidal canals (Cape Cod, D/Chessy) the current will add significantly to your speed over ground (SOG).
3 - in the right conditions sailing with a spinnaker can push the limit of the theoretical 'hull speed'.
Most of the time though you would be happy to get 5+ knots on a CD 25.
If you really want faster then consider a planing hull, longer boat (LWL), or a catamaran or tri (or powerboat).
thank you very much, you learn something every day, if you tell me all you know, i will know more than you, i will know what i know and what you know too.
The CD 25 has a similar shaped hull to my Tartan 27 (cutaway full keel), IIRC. Similar classic lines above the water line as well. The hull shape makes it 'sea kindly' or 'forgiving' but it wont point as high as a fin keel boat.
Sounds like a good starter boat to me.
Yeah - I was kind of joking with the 9.1. Bubb can do it with his Bene - but if you're doing 9.1 on a CD, you should probably get nervous. Things may not end well.
BTW, the Cape Dory 25 is a very different boat from the Cape Dory 25D. One has a small cabin and is outboard powered...while the other (25D) has an in-board diesel engine, standing headroom, no v-berth and the biggest head forward on a boat that size.
Hey Dog - that reminds me, what ever happened to that dude that was going to pull his keel, strap a 250HP Mercury to his transom and see if he could get the boat to plane? Can't remember the type of boat - but it was pretty funny.
I wouldn't know fast if it slapped me in the face. With a PHRF averaging 270, a dirty bottom (no snarks there please), and a blown out main... If I ever see "hull speed" on my C22 I'll give up drinking.
No wait... I'll get back to you all on what I would give up.
Yeah, I got hammered. We spent Fri and Sat night out on the boat. I sailed Fri with 15 gusts to 25. I had my only reef in and was flying a 135 genny. A C22 is tender, but this was down right scary. Ended up dousing the main since I could not flatten it enough and finally anchored both nights to lick our wounds and do some fishing. Sat seemed pretty tame but I was in a cove, it was Fri mid afternoon that got us.
We did catch 12 cats, kept 6, so the eating was good. Cold and wet but still a great weekend on the lake.
Cool. We sailed Saturday and overnighted. Nice sailing Saturday if a bit light. I looked it up and we got 50 knots early Saturday am. That's what beat us up.
Yeah, I remember getting up really early Sat to check the anchor. It was blowing something fierce. Course I was still half drunk so I blew it off and went back to sleep once I knew we were not going anywhere.
I'll be looking for you. We sail out of Yacht Harbor (now Sail and Ski Marina), at mile marker 14. I think you are closer to the dam around AYC? Looking forward to meeting you.
Everybody here knows that hull speed is not an absolute limit right? It's actually just an equation that estimates the point on the speed vs drag curve where the curve suddenly turns up rapidly. So effectively adding more power produces a greater speed, but at a smaller and smaller increment. So on a boat like the Cape Dory two horsepower might produce the hull speed, but it would take say 15 hp to produce one extra knot.
Not to be overly technical, but you are correct. "Hull Speed" is a term most often used by amateurs and not architects. The general formula for others reading this is.
V(hull speed) = 1.34 X Square Root of LWL
A more accurate calculation is the Froude number which you described:
Fr = V / square root of (gravitational acceleration X LWL)
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