Boat sails faster on starboard tack

[BarryL]

Hello,My boat is faster on a starboard tack than on a porttack. Any ideas why? I have done some experimenting,and the starboard tack is always faster. The differenceis not huge, about .5 kts, but it's pretty consistant.Why is that, and how do I fix it?Thanks,BarryBarry LenobleNoble Prize1986 Newport 28Mt. Sinai, NY

 

[jimq26]

What instrument tell you that?

If you are reading SOG on your GPS there could be some rigging adjustments required. If you are getting the reading from a bottom paddlewheel type transducer, then that's probably caused by a deflection of water by the keel.My experience anyway.

 

[Franklin]

Me too

My h376 also seems to be faster on the starboard tack as well. I figured it is because the fuel tank is on that side and the holding tank is on the port side (fuel tank full and holding tank empty) but I'm not sure.

 

[Guest]

Most likely it's rigging

Barring the keeldeflection mentioned above, it's probably rigging.Some racers will actually setup a boat like this on purpose if the course favors one tack over the other. Granted .5kts isn't going to make a huge diff, but you get the idea.Your mast is probably leaning slightly to starbord which puts it a little more perpendicular to the wind on the stbrd tack.Play with the shrouds and see what happens.Don't be afraid of rig tuning!

 

[Don Guillette]

Barry: This happens with 95% of the boats I've sailed on at that includes cruiser and club racers. I'm no engineer but I think it is primarily rigging as Guest has suggested and weight distribution as Franklin pointed out. There are probably other reasons also.Your best bet to correct the situation is to have a rigger check it out. While he is at it, have him check the condition of your rigging. In my case, the checkup was worth the $90 I spent because he found 2 cracks in the swages at the top of the mast. Had they let go, it certainly would have ruined my day!!

 

[RichH]

How are you determining speed?

If you are using a GPS and the tidal/current flow is either slack or flood then the differences are probably rigging related.If however you are using a speed/log and its not mounted directly on the centerline, then the differences of flow past the paddlewheel will be quite different from one tack to the other, especially when heeling. The flow streamline patterns when at heel and especially if the keel is 'lifting' hydrodynamically to windward will be very different. Only way to accurately use a paddlewheel transducer is to either mount it directly on the centerline OR use two in a symmetrical pattern, etc. - (requires switching on different tacks). Offset from the centerline - Its a natural 'calibration/usage' error. For true precision just about ALL 'gauges' and instruments (pressure, temperature, speed, etc. ) need an added mathematical calibration 'correction' to be used accurately.

 

[Paul J. Rusyniak]

‘Cuz

the boat knows it’s privileged!!!Pauls/v The Lord Nelson

 

[SoupyT]

Splendid name

Paul: A splendid name for your boat! Particularly this year!

 

[Guest]

Not to overlook the obvious.....

There's not an outboard dipping into the water on the port tack, is there?!

 

[Paul J. Rusyniak]

Soupy...

THANKS!!!I’d love to sail on October 21 this year, but our marina operator starts getting kinda antsy about pulling boats about that time. Maybe…………Pauls/v The Lord Nelson

 

[Don12364]

Nah

Its the log being mounted off the centre line of the hull.

 

[Tom S]

I agree with Donalex

I too notice a difference but I think its because my knot meter is off center on my port side near the bow, so I think the flow of water is that much different from one tack to another. GPS does not corroborate the speed differences I see on two differnt tacks -- but it is different

 

[Terry]

Rigging?

I had recently re-rigged after moving my boat and thought it was right. Measured from the top of mast to the sides to center the mast etc. After sailing awhile it felt as though it sailed better/faster on a port tack. What I did was layed on my back and sighted up the front of the mast. Ugh. What I didn't do was adjust the lower shrouds correctly and the boom was bowed from top to bottom. Not bad, but enough to notice.  I'm in the rigging crowds corner...Sail on....Terry

 

[Alan]

Yep!!

Had the same problem. Relocated the knotlog on center in front of the keel with a deck plate in the floor to leave easy access for removale when on the mooring and the problem magically disappeared, go figure that!!