Reference to Magical Armchair’s question, I had the saildrive seal/diaphragm on my B36(2002) changed during the winter months of 2010/11. At the time I was a brand new owner of a second hand boat, but with intentions of allowing the boat to be used for charter work, and so it needed to be in tip top condition. I was concerned that the seal was more than Volvo’s recommended seven years of age maximum, and so had it changed. I need not have worried, the old seal came out looking as good as new. It is in my estimation a pretty tough and very hard wearing piece of kit. Ive since sold the boat, about two years ago. A friend has a boat that is not a Bavaria, but which has the same Volvo set up and his seal is now more than twenty years old and he has no intention of changing it yet. I have a feeling that someone, possibly within this group, posted a question asking if there were any known failures of the hull seal, and I don’t think anyone came back with an affirmative reply. You say that you dont really want to do the job, but are curious to get the experience. It would be easy for me with no boat of my own to say don’t bother, just leave it there, but I am quite happy to sail on my friends boat with his over twenty year old seal. So in my opinion, just leave it where it is and enjoy your sailing and maybe think about it in another ten years time.