Doyle Sails - Utility Power Sail

[Zednotzee]

Is anybody using one of these? If so, how do you like it?

Doyle Sailmakers: Utility Power Sail

[roverhi]

looks like the reacher/drifter I had on my Westsail 35 years ago. It was a great sail for reaching and light air. The high cut clew could be sheeted to a block on the boom. That opened up the slot between the main and headsail and was good for an extra knot on a reach. Could be used for going to weather in light conditions but definitely was not a high pointing sail.

[HobieFan]

Originally Posted by roverhi

looks like the reacher/drifter I had on my Westsail 35 years ago. It was a great sail for reaching and light air. The high cut clew could be sheeted to a block on the boom. That opened up the slot between the main and headsail and was good for an extra knot on a reach. Could be used for going to weather in light conditions but definitely was not a high pointing sail.

Forgive my lack of experience, but I just can't picture this block "opening" anything.

You're pulling the clew into the boom. Presumably, it brings the clew in closer to the main. This closes the 'leak' on the trailing edge and fills it up more like a spinnaker, eh?

Where does the phrase "opens the slot" come from?

[roverhi]

When you are on a reach with the main fairly far out and the jib sheeted to the rail or inboard, the slot between the main and jib is almost closed. That limits the amount of air that can get through the slot and kills lift on the main. Further, you are dumping the air from the jib onto the main at a very sharp angle which creates turbulance and further hurts lift on the main.

By sheeting to main boom, fairly close to the end, the slot is opened up and the exiting air from jib just has to follow the angle along the backside of the main without much change in direction or constriction. You arent cranking the clew of the Reacher/Drifter hard against the back side of the main. You are displacing the sheeting point of the jib well outboard to complement the boom angle of the main.

You can't do this with a deck sweeper Genoa as you lose the downward angle that a deck mounted block gives. This allows the luff to balloon hurting lift. You need a high cut clew like the pictured sail to make boom sheeting work.

Honest, moving the R/D sheet from the rail to boom on a reach added a full knot to the boat speed.

[roverhi]

The area between the main and overlapping headsail, or any headsail for that matter is called the slot. You want air from the jib to flow along this boundary to be as unrestricted as possible. It's the differential between the air on the face of the sail and the backside that creates lift and powers the boat. It's a principal discovered by the Bernoulli brothers in the sixteenth century. If the slot is closed at it's end by too tight a sheeting angle, the air flowing along the backside of the main is slowed and does not create lift.

Only in downwind sailing is the wind pushing the boat. With fore and aft sails, you are actually being sucked along by the pressure differential between the front and back of the sail. It's the same principle as an aircraft wing. The pressure differential creates way more energy than just the wind blowing against the face of the sail.

[Uliad]

We had a new Doyle UPS made a little over a year ago...Took delivery in Trinidad and sailed with it as far as Tahiti. We've found it useful in 5-20 knots of wind at a true angle of 90 to 160 degrees or so. Most of the time we leave it up and furled in front of the jib when not in use... but in winds higher than 25 knots, the top third of the sail will sometimes try to unfurl itself--not good!
The webbing at the head of the sail tore loose on our Galapagos-marquesas crossing after being up continuously in 18-22 knots of wind for three days. After beefing up that weak spot it has performed flawlessly. I would buy again from Doyle, but make sure that head webbing is stitched more robustly.

[Bash]

Originally Posted by roverhi

Honest, moving the R/D sheet from the rail to boom on a reach added a full knot to the boat speed.

It does this by allowing you to keep an open leech on the headsail.

[atexasex]

Can you use a UPS without the headsail?

[cortezsailor]

Island planet sails makes a CLASS sail that is made with 2.5 oz offshore light air Genoa , along the same lines looks interesting.



Sent from my iPad using Cruisers Sailing Forum

[Dockhead]

Originally Posted by roverhi

When you are on a reach with the main fairly far out and the jib sheeted to the rail or inboard, the slot between the main and jib is almost closed. That limits the amount of air that can get through the slot and kills lift on the main. Further, you are dumping the air from the jib onto the main at a very sharp angle which creates turbulance and further hurts lift on the main.

By sheeting to main boom, fairly close to the end, the slot is opened up and the exiting air from jib just has to follow the angle along the backside of the main without much change in direction or constriction. You arent cranking the clew of the Reacher/Drifter hard against the back side of the main. You are displacing the sheeting point of the jib well outboard to complement the boom angle of the main.

You can't do this with a deck sweeper Genoa as you lose the downward angle that a deck mounted block gives. This allows the luff to balloon hurting lift. You need a high cut clew like the pictured sail to make boom sheeting work.

Honest, moving the R/D sheet from the rail to boom on a reach added a full knot to the boat speed.

I'd like to try this trick with my 120% yankee jib, which has a fairly high clew.

Also, I bet you could barber haul the sheet downward to add some leech tension. Downside is you now have a web of ropes (add the preventer to everything else -- ouch!) which would be hard to reconfigure in a hurry -- maybe not a problem on a longer passage.

Thanks for reminding me about this -- I think I will try it at the earliest opportunity.


It occurs to me also that instead of sheeting to the boom, one could run a barber hauler from the boom end to tweak the sheet outboard. Then you will have the regular car position to control leech tension. Anyone try this?

[colemj]

We have one on a Facnor continuous line furler. It is definitely not a reacher/drifter sail. Think of it more like a fuller Code 0. It has a vectran torsion luff line that allows the luff to be set bar tight and straight for upwind work.

It works extremely well from 60-120* AWA in winds <17kts. With some tweeking (if your sheet leads aren't perfect for it), it works fine up to 40* AWA, and the luff can be loosened to allow it to work at lower angles - even DDW, although the top of the leach spills off a lot. On our catamaran, it is mounted on a movable bridle that allows us to pull the tack completely over to the windward bow - and it sets deep downwind well this way with the main still up.

It has no UV luff protection, so shouldn't be left in place. Also, ours will start to unfurl at the top quite easily - even in lower winds. We never leave it up when not in use.

If one is looking for a deep reaching or downwind sail, this wouldn't be my choice. If, like us, you have a relatively small, non-overlapping headsail that isn't very powerful in light winds, this is a tremendous boost for reaching in lighter winds.

We got ours just before leaving for the Caribbean, and haven't used it much since because we always have enough winds for the white sails.

Mark

[hsi88]

Haven't used it yet, but picked up a "Generator" sail from Peak Sails for my Catalina 30. Seems very similar to the UPS or a typical cruising code zero. Basically a lightweight 165% Genoa that was specifically designed for light air. Something that occurs regularly on the Chesapeake during the summer months. I am rigging it in front of my furled Genoa, so to tack I will need to sock it first (chutescoop). But suspect I will mainly use it on a steady reach and not so much when I'm beating back and forth into the wind.

[Drew13440]

Originally Posted by hsi88

Haven't used it yet, but picked up a "Generator" sail from Peak Sails for my Catalina 30. Seems very similar to the UPS or a typical cruising code zero. Basically a lightweight 165% Genoa that was specifically designed for light air. Something that occurs regularly on the Chesapeake during the summer months. I am rigging it in front of my furled Genoa, so to tack I will need to sock it first (chutescoop). But suspect I will mainly use it on a steady reach and not so much when I'm beating back and forth into the wind.

I've got Doyle sails that are the bee's knees, but I'm interested in one of these as well. A little concerned about you get what you pay for. Is it decently constructed and do you know if it fits yet?

[hsi88]

Originally Posted by Drew13440

I've got Doyle sails that are the bee's knees, but I'm interested in one of these as well. A little concerned about you get what you pay for. Is it decently constructed and do you know if it fits yet?

They seem well made. Surprisingly so for the price. I want to upgrade the hardware I'm using, but went ahead and hoisted it to check it out. I can actually adjust it to fly over the pulpit, so the fit seems good for a variety of conditions. Upwind, the idea is to tighten the halyard so it works like a genoa. Downwind, you can free fly it and pole it like a spinnaker although I will probably keep it tacked up front for ease of use. Will simply loosen the halyard for reaching or running. Sorry I don't have more experience with it than that. But I'm looking forward to using it a lot next year.

https://www.peaksailsna.com/the-generator/