Camper & Nicholson 30 - Which size Keel Bolts?

[DangerousPirate]

I discovered one of my keelbolts is going, so I'm thinking about replacing it soon. But I don't want to remove it and then start figuring out which size I need, I'd feel a lot safer if I can buy the right bolts in advance.

 

[Tranona]

Why do you think it is "going"? Is it a bolt going through the hull into the keel, or a stud with a nut on top? Often they look rusty but are actually sound and really disturbing them is a last resort unless you have a failure of the hull/keel joint and water is getting in. Suggest you post a photo of the offending bolt. As to size, they are probably 20mm or 3/4" diameter but you won't know the tread size and type nor length until you get it out.