Catalina 34

General Activities => Main Message Board => Topic started by: Eliosso on March 16, 2004, 07:13:38 PM

Title: Draft
Post by: Eliosso on March 16, 2004, 07:13:38 PM
I have 2 surveys on my 1989 C34 wing keel with 2 different draft specified, 3'10 and 4'3''
Has anyone verified exactly what the draft is?
Looking at the boat in it's craddle and taking an approximate measurement not knowing the exact water line, , I get closer to 4'3''.
Confused Paul
Title: Draft
Post by: Stu Jackson on March 16, 2004, 08:14:37 PM
It's theTILT TILT

My understanding is that the 3-10 flat wing keel when tilted (like hard on the wind) goes deeper because the fin part of the keep simply gets deeper.  That's the 4-3.

Stu
Title: Draft
Post by: SteveLyle on March 17, 2004, 10:48:45 AM
Suggest you avoid situations where 5" makes a difference.

Stu's probably right.  Keep it mind that when you're heeling approx. 180 degrees, you'll be drawing about 50 feet or so.  Badabing.

Sorry, couldn't help myself, I've got spring fever (and we just got another foot of snow).

Steve
Title: Draft
Post by: jentine on March 17, 2004, 04:36:42 PM
I have measured my wing keel and it is 4'3".  I have read that the 3'10" was an erroneous measurement.  Five inches doesn't make any difference.  If the water is only 4'3" deep, any obstruction is a major problem.
Title: Draft
Post by: cholder on March 17, 2004, 07:02:27 PM
Something to add to your considerations is that when travelling at speed your boat sinks relative to the normal water surface.  Think about the wave pattern at maximum hull speed when you have a half wave length starting at the bow and ending at the stern.  The middle of the boat drops into the bottom of the [half] wave length. Pushing the boat up out of the bottom of the wave is what takes so much power that ordinary sailing boats can't get plane.

If you think this sounds daft remember that fast ocean liners suffered from the same problem.  If my memory is right, one of the "Queens" touched bottom off the American coast when they should have had a few feet clearance.

Not withstanding this truth of science, if I get into water that's so shallow I have to worry I soon slow down a lot and turn round to deep water.
Title: Draft
Post by: Jim "SV Ohana" on March 19, 2004, 04:17:39 AM
Noted while paying for several surveys in the course of buying our present boat, some surveyors use stated specs some actually measure and look.
Confirmed 4'3" draft while straying out of the ICW a couple weeks ago.
Jim