I have an urge to whittle a hand full of hull shapes (with correct weight distribution and spar weights), take to the beach and see what happens.
That's Zonker's job, Steve. Yours is to test anchors. Stay in your lane.I have an urge to whittle a hand full of hull shapes (with correct weight distribution and spar weights), take to the beach and see what happens.
Zonker DESIGNS the shapes. I whittle and test (and film, of course).That's Zonker's job, Steve. Yours is to test anchors. Stay in your lane.
Okay, just make sure you attach little anchors to them and I think you'll get by on a technicality.Zonker DESIGNS the shapes. I whittle and test (and film, of course).
I like that Idea.Okay, just make sure you attach little anchors to them and I think you'll get by on a technicality.
Classic wave theory has the water molecules moving in a circle. The implication of this is that on the face of a wave, "down" as measured by say a pendulum, is normal to the water surface. This continues until the wave is steep enough that the rotation can no longer be circular as the accelerations required are too great, the water slips and spills down the face - it breaks. A ballasted monohull with no mass (curious concept...) would roll so that it was always unheeled with respect to the water surface. Of course its real mass and moment of inertia in roll resists this cyclical motion - one reason why a mastless boat may roll over more easily. Once the wave breaks there are many dynamics involving the boat's characteristics in play. At least that is my understanding of it.Yeah -- when the boat is lifted bodily up and falls vertically onto its side, the finer points of yaw characteristics rather fall by the way. (Tho you could say a boat with optimal broach resistance is less likely to find itself beam to a breaking wave, so the hydrodynamics are still worth considering.)
Ugh! It’s becoming, like everything, an anchor thread!!! Everyone needs a good one.I like that Idea.
A recreation of the '82 Cabo disaster.
If I remember correctly, most of boats that did not drag ashore were using CQR and Bruce.
that makes me curious - how much empirical testing of procedures like that are done in climbing? And are the 'bottom quartile' of climbers more knowledgeable with better judgement than the similar sailors?.....
Pretty much all ice gear falls under the category "psychological protection." Maybe it'll catch a fall, probably it won't, can give the leader a sense of comfort having something to clip a rope to. Ice climbers are a special bunch.that makes me curious - how much empirical testing of procedures like that are done in climbing? And are the 'bottom quartile' of climbers more knowledgeable with better judgement than the similar sailors?
to my uninformed eye, that particular anchor seems dependent entirely on the ice quality. Which he does not really mention/discuss (other than it should be dry so you can recover the rope). And I personally would be reluctant to give that sort of equivalent direction to sailors because someone would try to follow it in the equivalent of obviously bad ice.
OK, so let me phrase it in a non absolute way. Designers of "proper lifting keel" boats warn you that it is unsafe to lift completely the keel except in sheltered waters so I wouldn't do it.btw . . . I am not intending particularly to 'pick on, or disagree' with you . . . . but whenever someone uses absolutes ('always keep...', 'absolutely want to...', etc) it raises flags in my mind. My experience is that there are quite few absolute rules for yachts. Soundbites rarely adequately cover correct seamanship. It may just be your writing style, but it may also reflect a lack of breath of experience.
I would think with a centerboard boat the risk of capsize would be minimized in breaking waves with the board up for the simple fact the boat would skid when hit broad side. I don't have experience with a cruising centerboard boat in those conditions so it's just conjecture on my part. Of the one design boats I've raced we always pulled up the centerboard when deep. If some bite was needed when broad reaching we added maybe 1/4 board.There is a risk of 'knock over' (eg 70-90 degrees) with almost all designs (in breaking waves). And you build your boat for the south just assuming you are going to get knocked over every couple years (at the very least least). Empirically it seems (with a high degree of variability and noise) that the boats with board up may get knocked over more frequently but get knocked down (>90 degrees) less often than deep keel boats.
I was living in NYC on 9/11. I heard about the attack within a few minutes of the first plane, friend phoned me. The first thing I did was mentally review the location of the sailboat fleets on Manhattan - no way I was getting stuck on that island! Then we went to the bank and got $10,000 cash and my wife and I carried 10 gallons of drinking water into our cave in the sky and filled both bathtubs as the authorities closed the bridges and tunnels. We waited to see if there were more attacks - anything else, we'd have grabbed a boat and left.Back in the mid-1970s, when my wife and I and several of our friends first lived on boats, we used to say "when the revolution comes, we are ready to get away."
One of my favorite historical factoids is that back in the days of sailing navies before Harrison made a reliable chronometer, the British Navy had standing orders not to spend more than two weeks looking for Bermuda. If they couldn't find it, carry on to the next destination in their orders! Sure you could get on the right latitude and sail back and forth, but not as easy it sounds in a square rigger.....one of our approaches to Bermuda, the night before landfall we saw a sail on the horizon (sailing 90 degrees to our course). He called us up on the VHF and said 'do you know where you are? I'm trying to get to Bermuda but my GPS went out 2 days from Montauk'.
Designers of "proper lifting keel" boats warn you that it is unsafe to lift completely the keel except in sheltered waters so I wouldn't do it.
Can you provide links to direct quotes of knowledgeable designers saying that? I would love to read them, see what detail and context they provide. I am sincerely interested in educated insight about this.
One of my good friends sails a boat with what I think even you might consider a 'proper lifting keel' - 2.7m draft when it is down, 39% ballast ratio. They run with it up. And they have huge offshore experience (even more than I do). But their hull shape is NOT the vendee/open shape - and perhaps that makes a difference idk - I would be interested in learning. I actually would have thought the Vendee/open shape would give more initial stability so would be better rather than worse with the keel up.
I just use my sextant to keep my GPS honest these days....it's also fun to see how close I can get. Steadily inside 3 miles (and often inside 2) with waves under 6', with the error growing with sea state after that.I’ve nothing but huge respect for those who can cross oceans using a sextant (or none at all, i.e., using natural navigation). And I think it’s a way to connect with the cycles of your environment too, which ain’t a bad thing
The big difference between the Pogo and a lift keel is where the ballast position ends up.btw . . . I am not intending particularly to 'pick on, or disagree' with you . . . . but whenever someone uses absolutes ('always keep...', 'absolutely want to...', etc) it raises flags in my mind. My experience is that there are quite few absolute rules for yachts. Soundbites rarely adequately cover correct seamanship. It may just be your writing style, but it may also reflect a lack of breath of experience.
Can you find a stability curve for the RM10.50? I would be curious how it compares to a Pogo curve, which honestly does not look so terrible with the keel up - more tender certainly, but I also note shaggy's comment that it moved weight distribution aft, which I think, (again I'm not at all any expert on this aspect) would help running in strong stuff - when I was racing light boats we certainly tried to trim weight aft in those conditions..RM 10.50
we really need you to get your boat back and do a series of test runs in the gulf stream with 50 NEly :blink:. Quietly they will tell you running with the keel up is fine if you want to, just don't go broad reaching due to the loads this puts on the keel head.