Chiara’s slave
Well-Known Member
Once it’s dark, it’s hard to trim anyway, so more conservative is a good idea unless you have a rail full of sailing gods.
Going downwind.
- Thread starter Allan
- Start date
westernman
Well-Known Member
Even square riggers are faster when not sailing dead down wind. For instance:-
westernman
Well-Known Member
Some one mentioned rolling when going close to dead down wind.
This is rolling.....
This is rolling.....
westernman
Well-Known Member
Here is the design data for the Pogo 30 with a symmetrical spinnaker.
The green box at the bottom indicates the best true wind angle and the corresponding VMG and speed through the water for the best VMG directly downwind.
The green box at the bottom indicates the best true wind angle and the corresponding VMG and speed through the water for the best VMG directly downwind.
MADRIGAL
Well-Known Member
Same for dinghy cruising, in my opinion. Those long tracks dead downwind are a real headache for the tiller pilot (me), with the rolling we get in any significant seaway and being constantly on guard for the unscheduled gybe, or the Wayfarer's dreaded downwind "death roll".While going downwind with white sails (main+genoa) I d give some thoughts to the sailing ''comfort'' too, in particular during longer runs. Personally I am more than happy to avoid dead downwind and give up some VMG in favour of a boat which is rolling a lot less, it heels on a predominant side rather than playing the metronome and throwing people and stuff all over the place, needs less constant attention to the wind angle (risk of accidental gybes, banging sails etc), also when the wind is light the increase in apparent wind immediately benefits the wind steering and -despite hardly ever using it- I see the electric autopilot working a lot less when 20-30 degrees off the wind than DDW, the boat seems happier overall. When DDW was almost unavoidable, say specific coastlines etc, I usually have memories of rather miserable sailing, if at all possible I d always prefer broad reaching and jibing, happier sail for a longer time what s not to like
geem
Well-Known Member
We almost never hand steer on passage. The autopilot does it all. Every possible sail plan and direction. A good powerful autopilot and course computer is worth it's weight in gold
Chiara’s slave
Well-Known Member
Those make interesting reading for us. I don’t know of any for Dragonflys, but if they existed they would be quite different. Especially in how much wind is needed for Vmax, that really jumps out. The angles really don’t work for them to nearly the same extent either. In fact they’re little different to those for a heavy displacement boat. We do occasionally get sucked in by the Pogo hype, and think maybe we’d be better off. But no, we’ll just carry on whipping their asses, unless the course is a dead run. Useful to know just how deep you have to sail a mono, even on a planing boat.
Supertramp
Well-Known Member
When racing in a mixed handicap class of cruiser racers in sheltered waters very few if any would tack downwind. We once had a J class in our fleet which tacked downwind and would win every race despite not gaining on handicap on the beats. So if you can get beyond hull speed its an advantage.
When cruising in a heavy displacement boat then twin jibs poled or poled jib and main work well. Rolling can be a problem and where I sail its often caused by a swell running at a 45-90 degree angle to the wind - like having a quartering sea but without the wind pressure in the sails to damp the rolling.
I wouldn't alter course for boat speed but I have done for comfort. I would like to experience a cruising multihull running in cross swell conditions - I imagine more comfort but possibly some spray over the corners.
When cruising in a heavy displacement boat then twin jibs poled or poled jib and main work well. Rolling can be a problem and where I sail its often caused by a swell running at a 45-90 degree angle to the wind - like having a quartering sea but without the wind pressure in the sails to damp the rolling.
I wouldn't alter course for boat speed but I have done for comfort. I would like to experience a cruising multihull running in cross swell conditions - I imagine more comfort but possibly some spray over the corners.
westernman
Well-Known Member
Indeed, I was surprised not to find speeds greater than wind speed and also how relatively little was to be gained by gybing downwind, rather than running straight. Of course, if you are racing, that difference is significant.
geem
Well-Known Member
My experience of sailing a cat across the pond is that they are way more comfortable in following seas and wind than any monohull. You can leave the teapot on the table in 35kts of breeze and it stays there. I would like a monohull for upwind and a cat for downwind
Supertramp
Well-Known Member
And a Westerly Fulmar for berthing!My experience of sailing a cat across the pond is that they are way more comfortable in following seas and wind than any monohull. You can leave the teapot on the table in 35kts of breeze and it stays there. I would like a monohull for upwind and a cat for downwind
I discovered things I didn't know I had after one particularily unpleasant Bardsey Sound experience.
Chiara’s slave
Well-Known Member
Clearly, the vessel you seek is the sum of their parts. We have the cat advantage downwind, but will comfortably see off that Pogo upwind. In 16kn true, we’d reckon on 9kn TWS, at 40 deg true. With the teapot on the table, unless theres a short sharp sea, like the western solent on wind over tide. A bit short on space on a 30 footer mind youMy experience of sailing a cat across the pond is that they are way more comfortable in following seas and wind than any monohull. You can leave the teapot on the table in 35kts of breeze and it stays there. I would like a monohull for upwind and a cat for downwind
John_Silver
Well-Known Member
AI assisted Google says that some Dragonfly 35 polars were published by YW back in an April 2007 test. Before the dawn of digital - so its not available in YW app archive or as a web search (that I've been able to find, leastways). BUT Ragnar, on SailNet, was sufficiently struck, by the difference in the DF35's performance profile and that of a J/122 (displacement cruiser/racer), tested at the same time, to verbally describe their two polar diagrams:
Chiara’s slave
Well-Known Member
Thanks. I can of course picture the kind of polars very well, as I daresay can you, after your sail. I wonder if that was with downwind sails. At 120 true in 10kn we’d already be planing, maybe 11-12kn with the code 0. In 20kn we’d not be flying extra sails at that angle, and unless racing would be reefed. Racing, we’d sail at about 145 with the code 0 with 20kn of wind, on gut feeling. That would be being cautious. In 10kn at anything more than 120 deg ideally we’d use the asymmetric. Dunno if you got to try that, it’s over twice the size of the code 0.
Deeper than that 145, we start to really slow down. That affects us badly in club races, they’ll time it for the mono fleet to have the tide behind them both ways. We are round the windward mark well before the tide turns, faced with a dead run. We only do it to show them how quick we are in the water though.
Basically, we're a staggeringly fast boat on any point of sail apart from a dead run. Hence we tack downwind almost always. I have yet to see a mono where that is a speed advantage at 140 degrees. 160-165 though, is fast, and more comfortable. Even in an XOD on some occasions. The death roll on one of those has to be experienced by everyone once, so you can get a sense of perspective.
Occasionally it’s the other end too.
Deeper than that 145, we start to really slow down. That affects us badly in club races, they’ll time it for the mono fleet to have the tide behind them both ways. We are round the windward mark well before the tide turns, faced with a dead run. We only do it to show them how quick we are in the water though.
Basically, we're a staggeringly fast boat on any point of sail apart from a dead run. Hence we tack downwind almost always. I have yet to see a mono where that is a speed advantage at 140 degrees. 160-165 though, is fast, and more comfortable. Even in an XOD on some occasions. The death roll on one of those has to be experienced by everyone once, so you can get a sense of perspective.
Occasionally it’s the other end too.
geem
Well-Known Member
...
We made great use of this sail plan coming back across the pond last year. It helped us average 6kts for the crossing in predominantly very light winds.
Many other cruisers arrived on fumes having burnt all their diesel. We did a fuel drop for a Beneteau 473 that took 5 days longer than us. They said they reckon they had about 3L left in the tank.
One the nicest point of sail for us is a broad reach in 9kts and fairly flat seas. We can carry the 130% genoa, mainsail and mizzen staysail. This saves us the bother of hoisting the asymmetric. We can often make 6 knts in 9kts T as the wind comes all the way around to the beam. We often have to point a little higher initially to get the hull speed up, then bare away and adjust the sail accordingly. With this set up we carry over 1500sqft of sail without a kite.Clearly, the vessel you seek is the sum of their parts. We have the cat advantage downwind, but will comfortably see off that Pogo upwind. In 16kn true, we’d reckon on 9kn TWS, at 40 deg true. With the teapot on the table, unless theres a short sharp sea, like the western solent on wind over tide. A bit short on space on a 30 footer mind you
We made great use of this sail plan coming back across the pond last year. It helped us average 6kts for the crossing in predominantly very light winds.
Many other cruisers arrived on fumes having burnt all their diesel. We did a fuel drop for a Beneteau 473 that took 5 days longer than us. They said they reckon they had about 3L left in the tank.
John_Silver
Well-Known Member
Al (DF agent) wanted to. But, seeing as we were already making 20kts, under single reefed main & jib , (pedestrian to experienced tri types I know, but balistically fast to me!), I asked to try out gybing instead. Which actually surprised me more than the outright speed. In 20, gusting 25kts, true the helm was light, the boat was flat (as it was on the beat out). Main flipped over sweet as can be, every time, even for a tri novice.
Still wondering about handling in a seaway. Quorning not keen on chartering their Danish demo DF28 to a solo tri novice.
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westernman
Well-Known Member
I assume by delta, they mean the difference in the speed through the water between 10knots wind and 20knots wind when pointing (going??) in the same direction relative to the true wind.
Chiara’s slave
Well-Known Member
The ride can be challenging if it’s really short and steep. But then, so it would be in a similar length mono. We have been known to put a few rolls on the jib in order to brew up. In just big swell, it’s exciting, not challenging. You’ve seen the Adriatic charter boat? They’ll sting you a couple of days tuition before letting you loose.
Exactly. 11 knots faster at 120 deg. The reason we don’t see that is that we’re already fast, with a Code 0. The poor little girl simply won’t move any faster through the water come 20kn. Up around 20kn of boat speed, there’s just no more to come.
flaming
Well-Known Member
These are very similar to mine.
I'm faster upwind across all wind strengths. Faster, and better VMG downwind until over 25 knots, though the difference is much less than upwind. I don't have polars for 25+. At that point it's somewhat moot...
But the wind strength at which it's better to hot up and plane is very similar.
Here's a shot from the Doublehanded RTI this year. Top number is boatspeed, next is TWA, next TWS. Sailing pretty conservatively, with a reef in the main and the tiny kite. Fully crewed in the same conditions we'd have had full main and the big kite. For reference the big kite is 86sqm. This kite is about 50.
Chiara’s slave
Well-Known Member
I was surprised to see 35kn polars. Generally it’s kind of survival of the fittest at that windspeed. And sensible Dragonfly 920s stay at home. Exactly how does one develop a polar in wind where the difference between max speed and ‘a tiny bit too much’ is serious breakage?