Mondays 04/25/2011 Question and boating safety tip

CaptainScott · Post by **CaptainScott** » Mon Apr 25, 2011 6:10 am

Safety Tip:
With spring on the way, It is that time again! Many of us are already working on our boats, getting them ready for the water! Some of us have already hit the water! With the spring cleaning and prep work have you added the safety check for your boat? When is the last time you checked your fire extinguishers? Do you even have them? Have you ever bothered to whack your powder extinguishers to help insure the've not turned into stone? How about your medical kit? Have all the medicines expired? Seriously, how old is that sun tan lotion? Really? THAT OLD? Are you realling going to put THAT on someone? How about your flares? Are they dated? They should be! Are they expired? They should not be! Remember to store you expired flares in a separate and clearly labled container! You may get a ticket otherwise! Don't be that guy who has aspirin for the crew only to find the aspirin expired in 2007!!

Question:
I'm sitting dead in the water my sails flapping in the wind. I pull in the main and the jib such as to sail in a tight reach on starboard tack. The sails are perfect. The tell tails are exactly as I like them using true wind speed and direction. My boat begins to accelerate. As I gain speed I realize that the jib and main have begun to luff a bit . . . . What? I just adjusted them. So, I check the wind speed. No change. I check the wind direction. No change. Check my heading. No change. Since I sail salt water I even go so far as to check the currents. No change. I'm not in a river. Why is it that I went though all that effor to set my sails perfectly and to "the book" and now they are slightly luffing ? What happened and what can I do to fix this problem? What was my mistake?

EmergencyExit · Post by **EmergencyExit** » Mon Apr 25, 2011 7:34 am

Being a touch coy with my answer

- Even tho you say you checked and the wind direction truly did not change, it seems it apparently did after you picked up some speed ??

mcrandall · Post by **mcrandall** » Mon Apr 25, 2011 7:40 am

But something DID change!

You didn't account for apparent wind. The only thing that changed in your scenario is your relative position to the wind. Once you start moving, the wind appears to be coming from a slightly different direction.

You create you own wind, just by moving--a slight headwind. These two "winds" combine to form a slightly different wind (relative to the boat) direction that needs to be adjusted for.

Good advice on safety! Check with your friendly neighborhood United Sail and Power Squadron or USCG Aux for free safety checks! I'll post something later providing a checklist from the USPS for do-it-yourself checks!

mcrandall · Post by **mcrandall** » Mon Apr 25, 2011 10:56 am

E.E. you are a sly one!

lecker68 · Post by **lecker68** » Mon Apr 25, 2011 10:59 am

Captain the faster you go the more the apparent wind moves toward the bow so if they are close hauled you will need to fall off the wind a bit to fill your sails again.

Alanhod · Post by **Alanhod** » Mon Apr 25, 2011 12:31 pm

I am in agreement with those above.

I was not moving and the wind was moving past me.

I am now moving and the wind is still moving so everything has changed.

The wind I am in when it is moving is slower because I am now moving with it.

My sails must be trimmed again to maximize my sailing efficiency in the new apparent lighter air even thought the wind speed has not changed relative to a fixed position.

Bad Example here. When riding in a balloon the balloon goes where the wind blows you. When your on the ground ready to take off in your balloon you feel and hear the breeze blow by you. When your in the air the balloon moves with the wind and you no longer feel or hear the wind go by because you are now moving at the same speed and direction as the wind.

Thanks
Alan

EmergencyExit · Post by **EmergencyExit** » Mon Apr 25, 2011 12:47 pm

mcrandall wrote:E.E. you are a sly one!

Paul · Post by **Paul** » Mon Apr 25, 2011 9:17 pm

These guys are so obviously right, I'll try something else. After accelerating your jib and main may be too closely set to each other creating a backwind between the two. Let the jib out slightly and see if both stop luffing.

Caveat: Dirt sailor here. The first statement in the original post said something about getting our boats ready for the water... These things are supposed to go in the water????? Wouldn't know it by how long it's taking some of us!

mcrandall · Post by **mcrandall** » Mon Apr 25, 2011 9:32 pm

Well, at least they're not aids to navigation at Chatfield state park, eh?!

Bhacurly · Post by **Bhacurly** » Tue Apr 26, 2011 9:55 am

Right,

Roger your Vector Victor

Meaning, you need to add the true wind Vector to the apparent wind Vector and compensate your sail trim or heading for the change, which of course may change the vectors again, especially if you get more lift and then more speed, at least until your done accelerating!??

Paul · Post by **Paul** » Tue Apr 26, 2011 3:22 pm

OK, Mark... Zing!

mcrandall · Post by **mcrandall** » Tue Apr 26, 2011 3:24 pm

Ha-ha-haa!

CaptainScott · Post by **CaptainScott** » Sun May 01, 2011 1:27 pm

ANSWER:

Apparent wind.

For those in the know it is very abvious! However if you do not have a lot of sailing experience you might not know the difference between true wind and apparent wind.

The best example I can come up with is on a windy day stand on the dock. The wind you feel is true wind. Now jump in your car, go down the freeway at 60 MPH, roll down your window and stick your hand out! That wind is apparent wind!

When you sail your boat you will sail to the apparent wind!
As your sailboat accellerates through the water apparent wind becomes a factor!

I used to sail an 18' Solcat. On a nice day I could run wing on wing. The boat would accellerate to near true wind speeds such that the sails no lnger had enough wind on them to keep them full. The main and jib would go slack! The boat would then slow down. As she slowed, the sails would re-fill! It was a continuous cycle! I found it more fun to broad reach! LOL!

Scott

lecker68 · Post by **lecker68** » Mon May 02, 2011 11:14 am

excellent description of apparent wind and true wind. Thefaster you go the more you have to pull the sails in.

John K · Post by **John K** » Mon May 02, 2011 11:44 am

69Shark wrote:I used to sail an 18' Solcat. On a nice day I could run wing on wing. The boat would accellerate to near true wind speeds such that the sails no lnger had enough wind on them to keep them full. The main and jib would go slack! The boat would then slow down. As she slowed, the sails would re-fill! It was a continuous cycle! I found it more fun to broad reach! LOL!

Scott

I haven't had that problem going wing on wing with the Chrysler 22, it's not fast enough! I do have a preventer rigged up though.

BTW I've found that the C22 does wing on wing pretty darn well.

<---- see avatar

Alanhod · Post by **Alanhod** » Mon May 02, 2011 2:07 pm

I've done wing on wing as well a few times in my C-22. Works really well but I don't have the cool photo like you do.

I do not have a "preventer rigged up." Am I taking a risk I was not aware of?

Thanks
Alan

CaptainScott · Post by **CaptainScott** » Mon May 02, 2011 2:54 pm

Alanhod wrote:I've done wing on wing as well a few times in my C-22. Works really well but I don't have the cool photo like you do.

I do not have a "preventer rigged up." Am I taking a risk I was not aware of?

Thanks
Alan

If you are a carefull sailor you can prevent MOST accidental jibes!

A preventer simply holds the boom out towards one side of the boat or other to help prevent that accidental jibe.

Nice to have but not required!

Scott