88' draft of wing keel and rudder

[kable]

Trying to plan a trip that involves some docking/rafting and need to make sure I am safe ;>)

Searching this great site I see that Catalina 34's wing keel design goal was a draft of 3' 10" but ended up being about 4' 3" (4' 5" w/ weight)
http://c34.org/bbs/index.php/topic,1880.msg10020.html#msg10020
I don't like "abouts, estimates, etc." when it comes to calculating depths.
What do most people set as their minimum depth to play with?

Also, I question the rudder length.  Seems like people are saying it is 'about' the same as the wing keel but a bit shorter.
http://www.c34.org/faq-pages/faq-fin.html

My problem/question is the accuracy of this.
When I had my boat surveyed they pulled it out in a sling.  When putting the boat down into its supports, they had a block of wood on the ground for the wing keel.  Everyone was focused on the guys watching the distance between the wood and keel directing the crane that we barely noticed that the rudder hit the ground first.  Luckily I saw it and got them to quickly stop.  They added another block and everything was OK.
I took note of this and measured (now question the accuracy of my measurement) but the fact is the rudder hit the ground first.
Now, the ground surface was gravel/dirt, not exactly level and I suppose the exact location of the sling picking up the boat could tilt the boat 2"s or so and cause the rudder to hit first.

Just wanted to get your thoughts?

So my trip to Sucia Island, the charts at the dock show 1 fathom.  Tides during this trip do not drop below zero.  I have seen other sailboats docked there.

Would you do it?   

-kable

[Ken Juul]

6 ft at the dock should be no problem, I do it all the time.  If you are worried about the rudder, don't back in.  If the boat is floating on it's lines, the keel is the deepest part, the rudder should be a few inches shorter, unless a PO put a fin keel rudder on as a replacement.

[Craig Illman]

You should be ok in Fossil Bay with a wing keel and nothing less than a zero tide. But you should probably not go in there at Low-Low water because of possible rocks or mooring buoy anchors. Last time we were up there, there was a C36 anchored at the shore end of the mooring field with a fin keel. I think there was a -1 that day (the Thursday before Memorial Day). He probably just touched bottom.

Craig

[Jack Hutteball]

I have been OK at a minus 1.5' tide at the end of the new dock on the west, and just touched on the outside end of the north dock, same conditions.  I have a fin keel.

Jack

[Ron Hill]

kable : I know you don't like estimates, but people load their C34s differently?

i.e. I carried three anchors with a total of 80 ft. of chain on 200 ft. nylon rodes - for each anchor!!   Get the idea?

A thought

[Lance Jones]

Hummmmm. I have noted that the rudder IS deeper than the keel. The few times I have grounded Kitty's Cat (At very slow speed and in sand), the rudder is the first to ground. We were once grounded at low tide, in sand, the boat was level with the rudder in the slightly deeper water. It was about 3" in the sand.

[Ken Juul]

I need to correct my earlier post.  I pulled out a copy of the original lines plans.  If the boat is sitting on it's designed water line, the rudder and the shoal draft keel are at the same depth.

[Rick Allen]

This is a older video of my boat being splashed after some bottom paint. At 1:04 into the vid you can see the wing keel hitting the water just a nanosecond before the rudder. this of course assumes that the waterline is level..
Video:
https://youtu.be/A4rTrjvQbmo

Rick

[Fred Koehlmann]

We have a 2002 MkII with wing keel, and sorry to say but "about" is going to be the best it'll get when determining your draft at anyone point in time. We know that it should   be 4'-3", but I always assumed at least 4'-6", because of "whatever" we may have on board. And I always look for a minimum of 5'-0"water in calm conditions, because even dinghy waves can bouncy you about some. The greater the trough trough to crest is on the waves the more water I want.

I never sweat the "inches" because we never try to put ourselves in such a tight situation. A for whether rudder or keel is lower, depends, how much water is in your forward/aft water tanks, how much chain is in your anchor locker, etc.

[Ron Hill]

Guys : Thinking way back I believe this has question has come up before and Gerry Douglas has said that the rudder is the same depth as the wing keel.

I believe that if you are motoring the stern will be down (lower in the water), but sailing the stern will be higher.  Always noted that on the transom bilge pump exits.

A few thoughts

[Lance Jones]

Ron,
That makes total sense.

[kable]

Thanks everyone!

Had a great time at Sucia.  The first day was a -1.5 tide so just grabbed a mooring buoy.  The next day we were lucky enough to get an end spot on the north/east dock (not the optimal one).  Calm weather, went slow and everything worked out.  Can't wait to get my electronics completed.

Back to Sucia again this weekend.