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Boat Speed at Various Points of Sail
Posted: Wed Jun 18, 2008 1:06 pm
by JustSail
I thought there was already a similar thread on this, but I couldn't find it.
I know scratching out that last ounce of performance isn't important to most Mac sailors, but there are a handful of us who race and even more who enjoy squeezing that last little oomph out of the boat. I want to put together a collection of speed information so that we can compare notes, experiences, and maybe even some friendly competition.
Last year was my first year racing and it took me all season just to figure out what the heck was going on and how to not be last over the start line. It's hard to win when you give everyone else a 5 minute head start.
This year I'm focusing on boat speed. Trying to make sure that at each point of sail we're pushing the boat the fastest it will go.
I plan on making a chart or something and updating this first post with everyone's feedback for easy reference.
Please use the templates below when you post your speeds. Also please post in knots so it's consistent. To convert mph to knots multiply by .869
Also I'm open to any feedback to make this informative for everyone.
Boat: '03 26M
Speed: 5.2 kts (GPS)
Point of Sail: Close hauled
Wind: 15kts (Masthead wind meter)
Sea State: <1 ft
Sail Area: Main & Genny (furled to jib size)
Boat Mods: None that would affect speed.
Notes: Realized afterward that the outhaul was loose. Probably would have had less healing and more speed if that was tightened up.
Boat: '03 26M
Speed: 6.5 kts (GPS)
Point of Sail: Broad Reach
Wind: 15kts (Masthead wind meter)
Sea State: <1 ft
Sail Area: Main & Full Genoa
Boat Mods: None that would affect speed.
Notes: none
Posted: Wed Jun 18, 2008 2:07 pm
by Hardcrab
JustSail,
Good idea.
I would suggest a more descriptive term be used for "Point of Sail", e.g., "degrees off the wind", assuming "zero degrees" is dead ahead wind.
Maybe add a daggerboard/centerboard setting.
I fall into the group who likes to get that last oomph out of sailing.
To many variables to list, but you have a good handle to share info.
Posted: Wed Jun 18, 2008 4:49 pm
by Jack Sparrow
I too race the reason to make me a better sailor and the fun of squeezing every bit out of the boat
I have tried everything at the start line I find the best is to hit it a speed (started second once and only finished 1 lap behind)
Pointing is a problem they all point better than me hence I have an extra tack falling behind on every beat to wind
I race in the same conditions as you, the genny was no good needed a jib and run the spinnaker on the downwind legs
Boat: '07 26M
Speed: 6.5 kts (GPS)
Point of Sail: Close hauled
Wind: 15/20kts weather report checked against met web site
Sea State: <1.5ft
Sail Area: Main & jib
Boat Mods: everything that you can think off.
Notes:weight makes little difference in top speed just in acceleration
Boat: '07 26M
Speed: 6.9 kts (GPS)
Point of Sail: Broad Reach
Wind: 15/20kts weather report checked against met web site
Sea State: <1.5 ft
Sail Area: Main & spinnaker
Boat Mods:everything that you can think off
Notes: sending crew fwd makes a difference about .2/.3 of a knt (gps)
Jack Sparrow
Conclusion
Need a full set of racing sails now to tell the Admiral
Posted: Wed Jun 18, 2008 6:37 pm
by bubba
I don,t race I cruse, but my wife likes to race. This is crusing speeds.
We have bottom paint and lots of crusing ( TV, dingy, frig, furnice, 3 anchors, ect ) gear that might make it heavier
Boat: '07 26M
Speed: 6.2 kts (GPS)
Point of Sail: Close hauled
Wind: 12kts (wind meter)
Sea State: <1 ft
Sail Area: Main & 110 jib
Boat Mods: bottom paint.
Boat: '07 26M
Speed: 6.2 kts (GPS)
Point of Sail: Close hauled
Wind: 12kts ( wind meter)
Sea State: <1+ ft
Sail Area: Main & 110 jib
Boat Mods: bottom paint.
Boat: '07 26M
Speed: 6.5 kts (GPS)
Point of Sail: Close hauled
Wind: 35kts ( wind meter)
Sea State: <5 ft
Sail Area: Main on 3rd reef & 110 jib partly ferreled
Boat: '07 26M
Speed: 12 kts (GPS)
Point of Sail: running down wind
Wind: 35kts ( wind meter)
Sea State: <5 ft
Sail Area: Main on 3rd reef & 110 jib
Boat: '07 26M
Speed: 10 kts (GPS)
Point of Sail: running down wind
Wind: 15kts (wind meter)
Sea State: <1.5 ft
Sail Area: Main & racing spinniker
Boat Mods: bottom paint.
Is this the info you were looking for?
Posted: Thu Jun 19, 2008 1:29 am
by hmb-barry
Don't forget Tides & Currents - can make a 3 or more knot difference in some places....
Posted: Fri Jun 20, 2008 8:09 am
by bubba
I didn,t add the spring run off with a current of 11 mph on the river.
Posted: Mon Jun 23, 2008 5:11 am
by brianhar
This sort of data is great. I agree that the angle of wind would be an added benefit, however the general pointing range is OK.
I have only started racing my boat in the last couple of months, however I've been plagued by light airs, and full balast = last. I can't measure boat speed since I accidently tossed the GPS overboard whilst fighting the mess of just white ropes (not anymore!).
I'm glad to have my thoughts confirmed in regards to the boat being pretty good off the wind, once it's got a bit of wind to play with. Very promising.
Keep the data flowing!
Posted: Mon Jun 23, 2008 7:22 pm
by baldbaby2000
Boat: '07 26M
Speed: 6.2 kts (GPS)
Point of Sail: Close hauled
Wind: 12kts (wind meter)
Sea State: <1 ft
Sail Area: Main & 110 jib
This seems pretty fast! I assume this is true wind speed not apparent?
Re: Boat Speed at Various Points of Sail
Posted: Thu Jul 17, 2008 3:01 am
by John Christian
Boat: '07 26M
Speed: 1.8 kts (GPS)
Point of Sail: Beam Reach
Wind: 5kts
Sea State: <1 ft
Sail Area: 150% Genny
Boat Mods: Bottom paint, DF70 disconnected from steering and raised, yellow/green Hot N' Tot trolled on 10# Berkley Fireline
JC
Re: Boat Speed at Various Points of Sail
Posted: Tue Jul 22, 2008 6:50 pm
by David Welch
Does anyone have any polar diagrams for Macgregors? I would love to have one for my 26s.
Re: Boat Speed at Various Points of Sail
Posted: Tue Jul 22, 2008 7:21 pm
by Frank C
JustSail wrote:I thought there was already a similar thread on this, but I couldn't find it.
See David's comment, below. No, they don't exist but they have been discussed.
You both need to search on the term,
polars ...
David Welch wrote:Does anyone have any polar diagrams for Macgregors? I would love to have one for my 26s.
Re: Boat Speed at Various Points of Sail
Posted: Tue Jul 22, 2008 9:07 pm
by David Welch
Frank C wrote:You both need to search on the term,
polars ...

Sorry, I just searched for "polar diagram" and "Velocity Prediction Program". I didn't think about just searching for "polar".
