I know that this will upset the purists amongst you (assuming anyone is reading this) but I am not a fan of Wilcox Crittenden sea cocks. These things are bullet proof and will last forever BUT they require annual maintenance and they live in the bilge. Now, I am happy to visit the bilge on occasion, but mostly to recover bottles of wine and rum stored there. Since child labor is outlawed and I am unlikely to get more supple and/or thinner with age, working in the bilge is a definite no-no. The plan is to replace them with Groco seacocks as per the attached link;
http://www.pbase.com/mainecruising/replacing_thruhullsIn the interim the existing 12 seacocks had to be freed.

Some had been in hiding for some time (possibly 30 years?)

A closer look.

Access to the after starboard two seacocks required an additional access hatch. This has been retrofitted on most Whitby's by now. This is my first attempt on TIH and may be enlarged later. The red thing on the left is a Fein Multitool, every boy should have one.

Now Wilcox Crittenden seacock maintenance is a simple 12 step process.
1. If the boat is in the water dive under the hull and ram wooden plugs into ALL of the holes in the boat.
2. Gain access to the bilge by lifting several deck boards, move wine/rum out of the way etc.
3. Lie flat on your stomach while placing all necessary tools close at hand.
4. Reach deep down into the bilge and try and move the handle of the seacock. It won't.
5. Reach behind you and grab the correct spanner. (do not ask your wife, she is busy).
6. Release the first nut then the second one.
7. With the mallet (which you have held in your teeth, until now) gently (haha) tap the end of the shaft to free barrel of the seacock. Now try and move it.
8. If that doesn't work, reach back for a pliers, remove the split pin from the shaft and remove the handle.
9. Apply a large Pipe Wrench to the end of the shaft and apply 200 lbs of pressure on the very end of it. This will involve sticking leg deep into bilge via a sharp edged fiberglass hole and jumping up and down.
10. When it finally moves (and it will), clean blood and skin off of wine/rum bottles and bandage leg. (Wife may help with this but do not expect any sympathy, after all the same thing happened last year).
11. Disassemble all parts, wash in kerosene, re grease and reassemble (do NOT drop any parts deep into the bilge).
12. Dive back in the water and remove the plugs that have now swollen in size, remembering that sharks are attracted by blood.
Repeat on the other 11 seacocks, annually!