I use to get in trouble: disappear along the coast for more than 8h, and hardly be able to walk or speak once out... try that with your mum! A good day was a day spend under water, and dry land will no longer exist until dark.
That doesn't have change, a good weekend is drive on friday to my spot, and spend the weekend under. With a kayak I may spend 3-4 h max paddling, but the rest is under as soon and long as I got light.
Anything attract my attention, and a cave is a marvel of live forms to observe. An friendly octopus is an endless entertainment of shapes and colors. A moray eel, a ray, a crayfish, an anemone... anything get me down for hours, and time flow unconstrained.
Spearing is about the same, get good fish takes time, try to see or shoot an exceptional fish takes for ever. And 6h is not usually enough... I may be getting softer, but is never time to get out!