I totally agree with everything said above. If you want to put the time in the oil based varnish's look the best. But, it takes a tremendous amount of time, effort and if it is on the outside of the boat, maintenance will take a tremendous amount of time as well.
While restoring my boat I began the project with McClosky Man O War oil based varnish Gloss. Days and in some cases breaking up the work into weeks are required and the mahogany I finished looked like a dining room table quality finish.
My boat is used hard with multiple friends running downriggers gaff's, nets, etc. which means damage will happen so I felt that I needed to make a change to something that was more user friendly to maintain.
I made a switch to Totalboat Halcyon Rugged Amber Gloss. It is a water base Varnish that is incredibly easy to use. It can be re-applied in 1 hour up to 5 coats in one day so the work goes fast and the finish is not bad. Best of all it comes in a bag, you can poor what you plan to use into a cup and when you finish poor the remaining unused portion back into the bag. Cleanup is as simple as rinsing off your brush and cup into your sink.
To prevent the sun bleaching out the wood under the finish I used Minwax Pre-stain then Zar Oil Based Interior wood stain in 120 Teak Natural color and then top coated it with several colors of the Halcyon. I will say when you take a close look it isn't as rich looking as the oil based Varnishes. But it is close enough that nobody noticed the difference.

- Whaler Pic stern bulkhead starboard to port transome side 4-6-21.JPG (105.36 KiB) Viewed 2528 times
In this picture are the two different finishes. The mohagany on the side of the wall is the oil based varnish. The top cap is 6 coats of Totalboat Halcyon. The difference is more prevalent in the picture than when you look at it in normal daylight.
I used the Pre-Stain, Zar 120 Teak Natural stain and Totalboat Halcyon on the gunwales of my 1980 Revenge 22 as well. They came out beautiful.