Buoyancy control in scuba diving. All instructors worth their salt will insist that their students can achieve a certain level of proficiency before they will put their name on the certification
and sign the student off as a bona fide open water diver.
The whole course main emphasis revolves around good buoyancy control from the very 1st session inwater and continues on till the last boat dive where the student can by then demonstrate to the instructor the ability
to have good control if not mastery of their buoyancy while swimming underwater. A prerequisite of all the diver certification agencies.
The ability to be in control of your position while underwater can
prevent a lot of potential mishaps, crashing into a reef breaking delicate corals, or avoiding injury to the diver's air spaces,or swimming straight into the path of a free floating jellyfish.
Sting from most jellyfishes arent lethal except for a few species,yet can be excruciatingly painful.
On the other hand ,if the skill is mastered, the enjoyment factor is