Varnish
The time and care needed to varnish is more then offset by the years of a "maintainence free" interior. However, I would be sure to read, read, read about varnishing techniques. You might want to chect out INTERLUX's web site for information on varnishing as well as different types to use. On most interior surfaces a UV additive is not necessary, but on surfaces where it would be desirable (such as the companionway entrance) you have to use a gloss varnish or polyurthane since the gloss is the only one to have that additive. Be forwarned, boat oweners are a compulsive lot, those who decide to varnish will experience new heights of compulsiveness! Once I touched the teak with that first brush stroke and saw the warm glow that resulted I was hooked and wanted to turn my boat into a floating violin. LOLGenerally speaking the polyurthae applies a bit easier and levels itself better then varnish. It is also easier to work with and is not as sensitive to climate and temperature. It is a harder finish then varnish, which may or may not be desirable depending on where used. Varnish, on the other hand, seems to have a warmer and softer "glow" in its appearance. I have used both and still am having a difficult time deciding on which to use on my newly purchased used boat.My "dream" boat is the Cherubini 48. Aside from the remarkable workmanship, quality of construction and aesthetic of its "look", I am amazed at the varhish work; both inside and out. Look in the archives or under the heading "The Cherubini Hunters" for a great lesson in varnishing by John Cherubini. If I were ever going to varnish exterior wood I would use his technique. You will definitely get a great deal of pleasure from all the effort of varnishing your boats interior. One of those pleasures is the beautiful look and feel to the wood when anchored in a nice quiet cove some dark night with the light of an oil lamp playing off the varnished surfaces.Good luckPS