C320 Keel design - Old vs New

[Jeff Church]

I was just working in the yard and noticed that a newer 320 (it has the large hatch in the aft cabin) has a different keel and rudder than my '98. My keel and rudder are 4.5" deeper and my keel has smaller wings. I looked at a '98 brochure and it lists the draft at 4'3". The current brochure contradicts what I just measured. It lists the draft at 4'10.5". I'm actually pleased with the deeper keel and rudder because of the better windward performance potential, but I am curious, does anyone know when the change took place and why? I have pics that I can post if anyone cares to see them.JC

 

[Ron]

Interesting

I have a 2000 model (hull #831) and didn't realize that it had changed. Next time I'm out to the boat I'll do some measurements to confirm.If the keel is deeper, then smaller/lighter wings can be used to achieve a similar turning moment. Smaller wings are probably less likely to "anchor" the boat in the event of a grounding, too (something other wing-keelers have noted).You might try posting an email to Catalina or the C320 Intl Association (see the "Links" tab on this site's homepage).--Ron

 

[Jeff Church #535]

Measurements

Ron,My rudder is 53" long from the lower rear corner to the upper rear corner, vs 49" for the newer boat. The keel is 34" from the lower front corner straight up to the center of the radius where it meets the hull. The newer boat measuered 29". Check the attached pic to see the difference in the wings.JC

 

[Joe Barrett]

Deeper Bilge

I think the newer boat has a deeper bilge than the old. I have hull #689 with the deep bilge and it draws 4"10". I think some older designs had the shallow bilge and I think that may be what yours is. They must have made the keel and rudder shorter to accomodate the deeper bilge without increasing the overall draft of the boat.

 

[Jeff Church #535]

I don't think so...

According to the 320 Int'l Assn web page, the shallow bilge ended with hull #355. Maybe they switched to the new parts for economic reasons. Could they be using the same parts as the 310 and saving some production costs?JC

 

[Jeff Church #535]

Checked around the yard again...

...and found that the 310 and 320 are now sharing the same keel. They measure out to the exact same dimensions, so Catalina must have changed the 320 to accomplish some manufacturing economies when the 310 was introduced. My first clue (dah) was that the ballast specs for both boats are 4400 pounds for the wing keel. Not that it's a big deal, but I was curious when I saw the difference between my boat and hull #915 (approx). JC

 

[Jeff Church #535]

Checked around the yard again...

...and found that the 310 and 320 are now sharing the same keel. They measure out to the exact same dimensions, so Catalina must have changed the 320 to accomplish some manufacturing economies when the 310 was introduced. My first clue (dah) was that the ballast specs for both boats are 4400 pounds for the wing keel. Not that it's a big deal, but I was curious when I saw the difference between my boat and hull #915 (approx). JC