I think the issue of the fin rider is interesting There can be a wide range of interactions with animals that just do not harm them. Lord knows, I have had enough manatees come up to be petted, and I have touched sharks, groupers, and other critters that approached. However, even though my actions do no harm by any objective standard, they might cause the animal to change its behavior by leaving the scene. This is especially true if multiple people want to interact as opposed to observe (we tend to forget the principle of cumulative impact). So, even though a 1 microgram no-see-up cannot "hurt" me, if enough of them "interact" with me I will leave the area, which would ruin it for all the other no see ums that want to see me. Same here: the 40,000 pound whale is fine, but there was a chance the fin rider might have ruined things for other people who wanted to see it. Didn't happen this time, but it doesn't mean it's not a valid concern.
I do not adhere to any hard and fast rule except for one, I do not switch from observation to an interaction unless the animal approaches me and the circumstances suggest that an interaction would not be an irritation to the animal. I do not chase or otherwise initiate the approach. Yes, it's a judgment call and might vary from person to person. Just do the best I can, but I don't believe in depriving myself of using my sense of touch as an absolute rule.
