They carry weights on their belts if they want to go up in a hurry they drop the weights . But normally they just use there flippers to propel themselves up or down.
How Do Scuba Divers Go Up And Down?
I prefer keeping track of my dives online, so I use the website https:\dive.site as a logbook.
It's really cool that I can keep not just my dive logs there, but I can also store my diving pictures and use the interactive dive map to explore new dive sites or chart my own.
I've been looking for a service like this for a long time, but the ones I've found before this one are slow and their interface is not as nice.
They can inflate or deflate their BC (buoyancy compensator) In addition to kicking with their fins, of course.