[hamiam]

First of all teak decks should be allowed to weather naturally and should never be painted, stained, oiled, etc. Deak has been the traditional decking material for hundreds of years. While I think modern boat builders use teak decks for their aesthetic beauty, teak has other advantages: it is cool under foot in tropical regions and has natural non-skid properties. High-end boats have teak decks because high-end boat owners can both afford the maintenance on the decks and can afford to replace them every 15-20 years. Given high quality materials and a good application to begin with, leaking should not be a problem.