Fascinating- I saw quite a few muskies on Conesus doing this a few years back

Lots of speculation and guessing. I see it just as much or more in the spring when water is cool and when fish are up shallow and with all size fish . At least with stocked tigers specifically. At times on Cowanesque you could see 4 or 5 at once down by the dam on a calm morning. On Otisco it's not uncommon to see several at a time and often they just pop up and do it after you're casting a spot for awhile or even after a boat goes through. Almost like they are just looking around lol. I contacted this Gord Pyzer a few years ago to ask what he knew of it and he had never seen it. He was amazed at the videos I sent him. We will probably never know for sure why they do it but if it is temp or O2 related it seems odd it happens so much in cool water also and early mornings. And if it's a swim bladder regulation thing it's odd that you see it so much in the shallows and flats. Just my 2 cents .