be careful
I can't claim to be an expert on the subject of compasses, but have picked up a few things from my recent experience with the Ritchie compass on my new-to-me boat. The PO did his own refilling of the compass before turning over the title to me. It looked good for a little while, but ultimately his effort failed. For one, a local compass repairman explained to me that it clouded because he refilled with a different fluid than the composition of the one originally in it. Also, the bubble in the dome grew over time until all fluid had leaked out. This happens as a result of the differences in heat of expansion between the liquid and the air in the closed container. I suppose the job can be done more cheaply by yourself, but I paid him $65 to completely clean it, replace the bladder, re-seal, and refill the dome with the right stuff in a vacuum tank (which minimizes the likelihood of air bubbles). You could also send the compass back to Ritchie for complete reconditioning for around $120 if you prefer. The Ritchie Navigation website has a list of local service agents. To me, it was more than worth it to properly repair the PO's mistakes, and do it right.
