I had a similar experience on survey day. The owner would not shut up. Thankfully the owner didn't show up until after the surveyor completed all the heavy poking and pinging on the boat. The surveyor was basically transcribing his notes and gathering miscellaneous specs like battery size and tank size. My wife who is a better people person than I went and had a chat with the owners so that I could talk freely with the surveyor.I flew to the MidWest to see a boat on the Great Lakes and the owner met the broker and I at their indoor storage yard. The owner absolutely sucked the air out of the room, telling me how great everything was they had done to the boat. A very friendly guy, but didn't want us to miss any little detail he was proud of. I think we had to stand next to the dinghy and listen to a speech on it for 5 minutes. I swear he was more proud of his dinghy than the mother ship itself. OOOPH.
I left that viewing feeling like I couldn't do what I went to do. If I opened anything, I got a 10 minute story. I think most owners would make this mistake, because it's too personal and they don't know how to sell.
Now, after the sale, I wouldn't mind sitting down with the previous owner to hear his stories. The previous owner had the boat for 30 years and knew the original owner. So like SanderO, he knows a lot of history behind his the boat. I just don't want an owner interjecting stories while I am inspecting the boat.