Sailing Faster on Starboard tack

Rich Stidger · Sep 24, 2010

I am no expert on this but the subject of different sailing speeds on different tacks has been discussed previously. Search the archives for some insight.

Regarding the Loos gauge- the Pro model is very easy to use. I would recommend buying or renting Brian Toss'es video on Rig Tuning. Then you need to get the specific specifications for you boat. The Loos Pro gauge is available in two sizes each covering a different range of wire sizes. Be sure you get the correct one for your boat.

If this is a one-time tuning and you aren't using this exercise as an opportunity to learn about rig tuning, you would probably be better served by hiring a rigger to check and adjust your rig. OTOH, if you unset your rig on a yearly or regular basis, you might want the capability to check and set your own rig. I know that I would.

Dan Johnson · Sep 24, 2010

Jack & Rich...

Jack: Before you start using a Loos gage on the shrouds, check to see that the masthead is centered on the boat's centerline. This could make one tack faster than the other by itself.

You can use the halyard taken to the same position on each side's rub rail as a quick check. If one side comes up short compared to the other, that's the side the masthead needs to be moved to. Your outers control that position. Once it's centered you can look up the mainsail track to see what lowers need to be adjusted to bring the center of the mast into alignment. Then, use the gage's charts to determine the correct amount of tension for each shroud size in use. Rough setting is 12 to 15% of breaking strength.

Rich: There's actually three Pro Loos gages. The biggest one is probably what Jack will need for his 350 and is quite a bit more expensive than the smaller two. I had to borrow one from a dockmate rather than spend that much for one for myself!

Snotter · Sep 24, 2010

My Out Island has 140 gallons of diesel on the starboard side and 170 gallons of water on the port side. The fluid level in each of the tanks affect how the boat sails on each tack. The rig was tuned with the boat level.

Where are the tanks on your boat?

druid · Sep 24, 2010

I would think you could get approximately how well your rig is tuned simply by lining up the mast with something straight up and down (plumb bob...), and checking the relative tightness just by pulling on the shroud.

Snotter pointed out another thing: make sure the boat is balanced. Again, lining up a plumb bob to the mast when at the dock, no wind or current, should tell you if it's listing one way or the other.

druid

shemandr · Sep 24, 2010

Yes all of the above are true. But still, most boats I've sailed on are faster on Starboard. I remember one writer or poster who gave the explanation that it is due to the coriolis force.
I am not a physicist and I didn't stay at a ......... but as I understood the arguement, the wind on starboard interacts with the sail in harmony with the coriolis force and on port tack it is in opposition to it- in the northern hemisphere. That's about the best I can offer.
We think wind acts on our sails straight from the direction of the wind but we need to remember that that wind is not making a straight course.
Time and time again I've heard of sailors driving themselves nuts with this issue, maybe unneccessarily because the basic assumption that wind encounters the sails the same on each tack may not be true.

Stu Jackson · Sep 24, 2010

most boats I've sailed on are faster on Starboard.

Ah, finally it dawns on me.

All those years of racing, when those big gorillas on the bow of boat closing in a warp speed were yelling, "Starboard, starboard!!!"

All it meant was that they were faster and I should let them go by.

Simple, eh?

Stu Jackson · Sep 24, 2010

druid said:
make sure the boat is balanced. Again, lining up a plumb bob to the mast when at the dock, no wind or current, should tell you if it's listing one way or the other.

I agree. What does one do when there is that lovely one side or the other LIST comes into play? For various reasons many of our Catalinas come from the factory with this built-in port list.

I think it's only to get folks active as newbies on these message boards so they can ask: "My boat has a port list, is this normal?"

Great way to get started with a whole bunch of new and very helpful friends.

rardiH36 · Sep 24, 2010

I've never done any empirical experiments with my boat on the port/starboard speed as Jack did. But, I'll opine along the already referenced lines that the natural port/starboad list of the boat probably has an effect. That is, does the boat have a list starboard or port even when just sitting in the slip?

I can't remember now on which tack my boat used to perform better. But it did. I first checked that the mast was port/starboard centered. (It was). However, I also had noticed that my boat had a pronounced list to the port side because of two batteries, the fuel tank and all the galley components being to port. So I put more water in the starboard FW tank so that the boat's port and starboard toe rails had the same measurement distance to the waterline. After this "balancing", I now really can't tell the difference between port and starboard when pressing into the wind. My speed instrument when the wind is to port shows a bit more knots, but that's because the impeller is mounted on the starboard side and the water flows across it faster when heeled to starboard.

Jack's speed difference observation was made in rather benign conditions where wind velocity wouldn't be causing his boat to heel very much. In this case, if the boat has a natural list, the difference in speed because of the list might be more pronounced than in heavier winds?

rardiH36 · Sep 24, 2010

Something to add to my post a few minutes ago: I think that I have read that in light winds, racing boats will shift people to the down wind side to create an artificial heel which increases the speed as opposed to the boat being straight up, or even "heeling" into the wind if all the crew is to windward.

Alan · Sep 24, 2010

Jack, question #1, is your knot log on center line? Mine and most boats I know of have the knot log off center which automatically favors one tack over the other. On my boat the knot log was installed on the starboard side. After I removed it and relocated it to centerline about 18" in front of the keel the readings balanced out and read accurately.

sinnettc · Sep 24, 2010

My Capri 22 sails about 1/2 knot faster starboard than port tack. Speed by gps on a lake with no currents. My rig is centered, my tension correct.

There are a couple of things I can think of, besides Coriolis effect . . .

My tuff luff foil has a bit of permanent twist at the top - Could be drawing better on starboard than port.

My tabernackle sometimes twists just a bit when I'm raising the mast; not more than 1 or 2 degrees but maybe it's having an effect. Winter project is to rebed and reseat the tabernacle .

Maybe I've got a lopsided hull - the pads are not exactly the same on opposite sides of the trailer but is that due to trailer construction or hull shape? Not sure.

jibes138 · Sep 25, 2010

Do you sail with your propeller locked so it won't spin or do you let it freewheel ? this can effect your boat speed. Also depending on whether it is a right or left hand propeller may have an effect. If you are using an outboard and it is on the port side it might be dragging in the water.

John · Sep 25, 2010

The opposite?

Dan Johnson said:
Jack: Before you start using a Loos gage on the shrouds, check to see that the masthead is centered on the boat's centerline. This could make one tack faster than the other by itself.

You can use the halyard taken to the same position on each side's rub rail as a quick check. If one side comes up short compared to the other, that's the side the masthead needs to be moved to. !

Unless I'm confused about something, it's the other (longer) side that the mast head needs to be moved to.

RichH · Sep 25, 2010

shemandr said:
Yes all of the above are true. But still, most boats I've sailed on are faster on Starboard. I remember one writer or poster who gave the explanation that it is due to the coriolis force.
I am not a physicist and I didn't stay at a ......... but as I understood the arguement, the wind on starboard interacts with the sail in harmony with the coriolis force and on port tack it is in opposition to it- in the northern hemisphere. That's about the best I can offer.
We think wind acts on our sails straight from the direction of the wind but we need to remember that that wind is not making a straight course.
Time and time again I've heard of sailors driving themselves nuts with this issue, maybe unneccessarily because the basic assumption that wind encounters the sails the same on each tack may not be true.

Yup, In the northern hemisphere due to the coriolis force the starbord tack is the favored tack, as when on the port tack the WAVES are a bit more 'head-on' due to the coriolis effect.

Joe · Sep 27, 2010

One of the primary skills a skipper needed back in the days of sail was to be able to trim the boat out correctly for maximum performance..... they would row around the vessel, observing how it sat in the water. Then they would redistribute the ballast in the lower sections of the boat to make the needed corrections until they were satisfied.

Often, at sea, ballast was redistributed as stores were consumed or certain sailing conditions called for a different trim aspect. To raise the stern or counterweight the windward side, for instance.

Even though modern boats have huge weighted keel fins fixed to the hull, there is still a lot of movable "ballast" in every vessel... especially cruising sailboats. So... it is necessary for any skipper, who is concerned with hull trim, to observe and correct the vessel's aspect by redistributing its movable ballast.

Fuel and water tanks are unlikely to be moved easily, but batteries, holding tanks, spare parts, food stores, ground tackle, etc. can certainly be relocated.

s sauer · Sep 27, 2010

Starboard?

As a Chesapeake Bay sailor, we need to account for the tidal differences on each tack. We have a slight list to starboard that I haven't corrected, so theoretically the starboard tack might be favored as it takes a little more pressure to heel the boat to port. However, that isn't necessarily going to show up onthe knot meter or GPS if tide and waves exert a stronger influence.
The wind generates the waves theoretically at similar heights on both tacks, but unless the wind and the tide are coming from exactly the same direction, you should see a favored tack due to the effects of current flow and wave height.

Douglast · Sep 28, 2010

Re: Starboard?

wouldn;t a laser level /laser plumb bob be a handy item for the mast for straight mast

Roger Long · Sep 29, 2010

The is a wind gradient caused by surface friction. You've probably noticed that there is generally more wind the higher off the water or land you are. This also effects the direction to some extent. Gust come from a different direction because they are the faster moving air from aloft dipping down to the surface; not an increase in overall flow.

Your sail will always have some twist and this will favor the slight difference in wind direction from clew to head more on one tack than on the other. Generally, it will be starboard.