[DelmarRey]

The problem with teak is the wood has a soft core between each grain. When you oil the wood it soaks into the core and not so much the grain. Over time that core is eaten away leaving the grain, a rolling finish.
You need to protect that soft core from decomposing unless you like the rough look. But in reality the wood is trying to split open.
When I had an all wood vessel in S. Cal. years ago I used Deks Olge. It''s more like a hard wax than a varnish. It comes in simi-gloss or hi-gloss. The weather doesn''t matter except rain of course. It dries in about an hour in hot weather but usually not longer than three hours on the cooler days. In the morning I would treat and coat and then have the vessel out by noon.
Once the wood is clean and smooth you''ll need to put on at least three coats to start. The more exposure to sun the faster the wear.
For me it would last about three weeks in the hot summer and about three months in the winter be for it showed signs of up keep.
Then I would give it a light touch with scottch-brite and another coat. It doesn''t crack like varish but evaporates. When you start to see a little color change, that''s the wood starting to show through. That''s when it''s time for another coat. If it goes too far, then a light sanding in the bad areas with 120 and a couple coats brings it back to original.