When I searched I was using the term 'whales' and my results listed it at a height of 150 meters, when I went back to search a few moments ago using different terms I received more detailed info (like posted above) being 150m horizontal (bubble) away from them. That is great to know as I can still fly above them for the most part to get the clearest few, but at an angle a bit to give the extra distance needed. You can fly lower with a permit, but they only grant those to researchers, looked into it out of curiosity - which is probably for the better given how some people might abuse it.
Last time we were out we had a humpback following us breaching next to the boat over and over. One of the splashes misted the crew on the bow. It was a calf just being playful. I see boaters 'chasing' the whales trying to get closer but sometime the best thing to do is just find a few and kill the engines. They seem to get curious of you and will approach you vs having the other boaters harassing them.