I have a 2005 Bavaria 46. So the sail drive is now 12 years old. The official advice is to to change the membrane every 7 years. My membrane looks fine from above, no cracking, and it seems quite flexible still. Considering the steep cost in this replacement, my thinking is to try and delay replacement for as long as possible. I was wondering what experience other forums members have had with this issue? Has anybody had an actual breach of the membrane by delaying replacement? Has anybody gone a very long time without replacement, say 15 years? If anybody has had this procedure done, what did it cost them?