My deepest sympathy and condolences to you and your family.
I don't know whether Doug was born a great teacher, or whether he had to learn how to teach. Either way, he came to it naturally. I took his beginner swimming class last year and vividly remember arriving at his pool (he seemed to own it) full of trepidation that first night, changing in that dingy changing room, and making my way upstairs to the pool. I sat poolside with a couple of other equally nervous nonswimmers, while Doug talked to us and made us talk -- why were we there? what were our fears? what did we think it would feel like to be in the water? He told us stories of all the people he had taught to swim (and one notable failure who had claimed he was trying to kill her and demanded her money back), and made us laugh at our hesitations. Then he told us to get in the pool and try to drown ourselves, to prove to us that we would float. Week by week, exercise by exercise, he taught us to swim, cajoaling, encouraging, insulting, and, yes, bullshitting (Doug never missed an opportunity to tell a good story or an old joke). About four weeks into the classes, I got it, and for the first time swam: I did about 20 lengths without stopping, and Doug's praise was unstinting. The next day he e-mailed me to tell me that watching me swim was the highlight of his day. I was so proud!
After the beginner class, I took his next level class, and this, too, started with a poolside chat. This time he added tests of ankle flexibility. The jokes and anecdotes were different, too, and the encouragement was more directed. The first night, he videotaped us swimming. His comment on my effort: "You can only improve." And I did. A few weeks later, in the middle of a drill, he stopped the class, and told me to demonstrate what we were meant to do. So I did, and when I had finished, he told the class, "Eight weeks ago, this person couldn't swim. Now he can." And he was right. I couldn't swim well, or strongly, but he had taught me how to swim, as he had taught so many other people.
I have rarely met someone as vivid as Doug. His personality filled that pool, encouraging his pupils to do better to repay his efforts to teach them. Physically, he filled the space too -- the way he carried himself, and moved, and the extraordinary grace with which he swam.
One night I arrived at the beginner class, and he was disappointed that I had come -- his neck was very sore, and he had hoped no-one would show so he didn't have to teach that night. It seems that his neck pain was the first sign that something was wrong. It's hard to believe that Doug is no longer with us. I had imagined taking classes from him into the indefinite future, improving my swimming, but at the same time finding out if at some point he started recycling the jokes and anecdotes. I will miss him.