Teak is an oily wood so eventually any sealer you put on it will bubble, discolor and split. Once it does it is a PITA to strip, sand and reseal. It looks great until it doesn't, though. Another option is to clean, brighten and oil with the Starbrite kit above. This is less labor intensive over time, but doesn't look quite as sharp as sealant, at least at first. The biggest factor is that you never have to strip it. A third option is to just to do nothing. The teal will turn grey but will still last a long time.