Another option:
Wood the
teak down to get it pristine,
sanding it to 220 grit. Apply a very thinned out (50-50) mix of thinner and
varnish. Let it harden, then give it a "haircut" with 220 grit to chop off the
wood fibers that absorbed
varnish and stood up. Then begin building up multiple coats with thinned (10-20%) varnish,
sanding between each coat. Do this until you are utterly sick of doing it (maybe 6-10 coats). Now admire it, absorb the compliments, and move to the next phase - ultimate protection. Give it a light sanding to remove all glossy spots, then cover with two coats of high quality single-part
polyurethane (Brightside or equivalent) in WHITE or WHATEVER LIGHT REFLECTIVE COLOR your
hull is. Go cruising the tropics, then when you return, remove the topcoat of white
paint, put one coat of varnish on the original, and voila!