The entire removal process was pretty easy. The centerboard weighs about 90 pounds. I can easily lift it and place it on sawhorses. A single person can lower it down and manuevere it from under the boat.
First thing: Safety! Safety! Safety! Take your time and think about what your are doing and how you are going to do it.
I have placed this info on the web to be a guide and also to help other Gloucester boat owners.
You will need approximately fourteen inches of clearance from the bottom of the keel. You may have to raise your boat to get this clearance. If your boat is on a trailer, lifting the trailer tongue might allow enough clearance to slide the centerboard out of the keel..
Obtain a scissor jack, the spare tire jack from your car will work just fine. Fully Extend the scissor jack. Place the scissor jack under the centerboard, where the supports arms attach to the centerboard. You may have to use a couple of cinder blocks to raise the jack high enough to reach the centerboard. Raise the jack so that it is taking a little bit of the weight.
Inside the cabin, remove the wooden vertical cabin support. The vertical supports also houses the rigging and steel cable that raises and lowers the centerboard.
Sticking up through the floor of the cabin will be a vertical flat tube, your centerboard cable runs through this and attaches to the centerboard. The flat tube is also sealed with a semi flexible sealant. We need to cut out the sealant with a razor knife, so that the steel cable will drop through the flat tube freely. Also you will see two flat pieces metal inside the flat tube. These are the supports arms that the centerboard is attached to inside the keel.
HINT: The steel cable stays with the centerboard when you remove the centerboard.
On the flat sides of the tube are two bolts and nuts with sealant. The bolts are securing the centerboard support arms to the flat tube. Carefully remove the sealant from the two bolts and nuts. Remove the nuts. I used 9/16 wrenches on mine.
Ensure the scissor jack is taking a little weight off the two bolts and slide the two bolts out of the flat tube. You may have to spin and wiggle the bolts to get them out. You may have to remove excess sealant from the upper bolt. I had to do this on my boat.
Lower the scissor jack that is under the centerboard, low enough to remove the pivot bolt. The pivot bolt attaches the support arms to the centerboard.
Lower the centerboard until it clears the keel, be prepared to balance it once it clears the keel. Carefully lift the end of the centerboard off the jack.
Carefully inspect the entire centerboard system. Since it is a hard to reach area, the centerboard tends to get overlooked when doing maintenance.
I am not sure if my rigging is the original rigging, so the photos I am providing may be different than yours.
Here are some of the problems I had found after careful inspection:
A marine fork is used to attach the steel cable to the centerboard. The fork on my cable was the wrong size. It was to short and when the centerboard was lowered, the fork would be put in a bind. Eventually this bent the fork and created a stress crack on the fork. This was very noticeable.
The centerboard had alot of wear. The area where the steel cable attaches to the centerboard was eroded badly. I sent the centerboard the to a local machine shop and had the attahment point place three quarters of an inch back and a three quarteer of an inch lower from the center-point of original attachment point. The original attachment is a quarter inch diameter hole that is on a machined out thin piece of the centerboard, which 0.200 thick.
