Catalina - Capri - 25s International Assocaition Logo(2006)  
Assn Members Area · Join
h.jpg Home.
a.jpg Association Forum
s.jpg Ships Store
c.jpg Cruising
r.jpg Racing
t.jpg Technical Tips
g.jpg Photo Gallery - New
o.jpg Boat Search - Updated
m.jpg Manuals & Brochures
3rdrpt.jpg Swap Meet
l.jpg Links
f.jpg Officer Flag Line & Staff
b.jpg Bylaws & Constitution
 
1.jpg Members Area
1.jpg Join the Association
 
Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
 
Association Forum
Association Forum
Home | Profile | Register | Active Topics | Forum Users | Search | FAQ
Username:
 Password:
Save Password
Forgot your Password?

 All Forums
 Catalina/Capri 25/250 Sailor's Forums
 Racing Forum
 The vagaries of lake sailing		  New Topic  Topic Locked
 Printer Friendly
Author Previous Topic Topic Next Topic  

Derek Crawford
Master Marine Consultant

Member Avatar

USA
3324 Posts
Initially Posted - 07/12/2009 :  10:08:16  Show Profile
We were racing yesterday in our Summer Series. The weather mark was close to the dam and as we approached in a nice 6-7k breeze we were suddenly and without any warning hit by an estimated 35 - 40k blast. We were running a full main and a 150% genoa - needless to say we were suddenly standing on the side of the cockpit lockers with water at gunwale level! For the first time ever on the lake, with the mainsail completely dumped, I had to call for the genoa to be dumped as well. Five minutes later we were back in drifter conditions!
Derek Crawford
Chief Measurer C25-250 2008
Previous owner of "This Side UP"
1981 C-25 TR/FK #2262 Used to have an '89 C22 #9483, "Downsized"
San Antonio, Texas
Edited by - on

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts
Response Posted - 07/12/2009 :  10:54:54  Show Profile
Sounds a little like what I guessed was a "microburst" that hit our daysailer years ago on Long Island Sound... Under a partly cloudy sky with light breezes, we were hit by a blast--I couldn't even figure out which way it was coming from! It was more like straight down than from any particular direction, slamming the main from side to side while the boat was losing steerage. Then just as suddenly, it quit.
Edited by - on
Go to Top of Page

Derek Crawford
Master Marine Consultant

Members Avatar

USA
3324 Posts
Response Posted - 07/12/2009 :  13:50:40  Show Profile
Dave - that's what I originally thought. But on thinking back I relized that it hit solely from our port side.
Edited by - on
Go to Top of Page

Steve Milby
Past Commodore

Members Avatar

USA
5909 Posts
Response Posted - 07/13/2009 :  06:51:59  Show Profile
As I understand it, a microburst is like a stream of air that "pours" down out of the sky at high speed. When it reaches ground level, it radiates out more or less in all directions, somewhat like the stream of water from a garden hose when it hits the ground. If you're directly under it, it will seem to be coming straight down, but, if you're slightly to one side of it, it'll seem to be coming from one direction.
Edited by - on
Go to Top of Page

GaryB
Master Marine Consultant

Members Avatar

USA
4316 Posts
Response Posted - 07/13/2009 :  18:37:15  Show Profile
Were there any thunderstorms in the area? Normally microbursts are a result of cold air and rain falling from the core of a thunderstorm. As Steve mentioned you can be to one side of a microburst and get a steady flow from one direction.

I know this is way out there but... Depending on how close you were to the dam could it be that possibly the sun warming the face of the dam mixed with the local breeze was creating a strong thermal effect right down to ground/lake level? I know I've been on top of the dam in mid afternoon and had a strong breeze blowing while the water at lake level was smooth as glass and a few minutes later the lake had strong wind streaks across it. A few minutes later it was back to glass again. It was almost like the air was spilling over the top of the dam and down to lake level and then later lifting back above the water.
Edited by - GaryB on 07/13/2009 18:40:26
Go to Top of Page

Derek Crawford
Master Marine Consultant

Members Avatar

USA
3324 Posts
Response Posted - 07/14/2009 :  09:43:15  Show Profile
That's a nice theory, GaryB. The excess wind was in a limited area about 300 yards from the dam, and there was quiet water between the weather mark and the wild wind.
The second time around the course the windy area was still there but seemed just a little weaker and we mostly avoided it by stayimg on our port tack longer before tacking for the mark. There are hills on either side of the dam so there may have also been a venturi effect.
Edited by - on
Go to Top of Page

NautiC25
Admiral

Members Avatar

USA
957 Posts
Response Posted - 07/14/2009 :  13:38:37  Show Profile
That's what I was going to mention. You we're surrounded by 3 walls.
Edited by - on
Go to Top of Page

GaryB
Master Marine Consultant

Members Avatar

USA
4316 Posts
Response Posted - 07/18/2009 :  20:31:56  Show Profile
I was looking at an aerial photo of the dam a little while ago and noticed that it lies almost parallel to the prevailing SE summertime wind (I always thought the dam faced due west).

Like NautiC25 mentioned there very well may have been a venturi effect. The wind may have been coming around the hill at the south end of the dam (possibly even coming thru the spillway} and was re-curving around that hill and then following the face of the dam. The shape of that hill is almost like the top surface of an airplane wing. If the wind was in the right direction it would accelerate around that hill and then follow the face of the dam.

Who knows! Just glad everyone was OK.
Edited by - on
Go to Top of Page

NautiC25
Admiral

Members Avatar

USA
957 Posts
Response Posted - 07/20/2009 :  13:10:33  Show Profile
In contrast, I went to Canyon Lake yesterday and there was NO wind whatsover. I had to motor around just to get out there. :(
Edited by - on
Go to Top of Page

GaryB
Master Marine Consultant

Members Avatar

USA
4316 Posts
Response Posted - 07/22/2009 :  10:18:24  Show Profile
Wah Wah Wah! At least the water is pretty and you won't get eaten alive by who knows what chemicals like you do here in Galveston Bay! I'll be more than happy to trade places if you like!
Edited by - GaryB on 07/22/2009 10:18:56
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Topic Locked
 Printer Friendly
Jump To:
Association Forum © since 1999 Catalina Capri 25s International Association Go To Top Of Page
Powered By: Snitz Forums 2000 Version 3.4.06
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.