Originally Posted by GMFL
Curious, why would you suggest that? All common sense (and practice) would suggest otherwise.
The other advantage of doing it this way is that since you are loosing the anti slip properties of the teak by varnishing it, if you re caulk afterwords you will at least have some anti slip properties from the caulk. While you say no one is going to step on it or they will get thrown off the boat, you don't want that happening accidentally. Not to mention it would look much better as the caulk won't have the varnish and will have it's natural finish.
Looking at the surface I would not let it go grey, but I don't think I would be varnishing it either as it looks like it would be subject to too much wear if you actually sail the boat, as people do step on the combings, and drop winch handles and what not. So I would use something easier to touch up, like Cetol with clear gloss over it. It would be less slippery than a standard gloss varnish as well and easy to repair. Since I don't like redoing varnish every so often and prefer to spend the time sailing, I would take the easy route out and use a modern sealer.
And if you don't know what the previous owner used on it, then I would not be so confidant that the new varnish will stick to the caulk so well. He might have used a product no longer made, or something different than what you have available.