No, as they weigh about 6 ounces each. Not much! Also, swimming competition rules forbid it.
Air is more buoyant than water because air is less dense than water, and everything the thing that is less dense is always more buoyant than what is more dense than it.
the buoyant force of the liquid on the solid is more than the buoyant force of the air on the solid.
Continental lithospheric plates are more buoyant than oceanic plates, yes.
No, certain turtle shell shapes are not more buoyant than others. A turtle's buoyancy is not dependent on its shell.
Because they are more buoyant than the water.
yes
Water is denser than air.
Yes, hot air balloons are less dense and therefore buoyant ============================================ Hot air balloons are buoyant to the extent that the weight of the hot air in the balloon is lighter than the free air. When the difference is more than the weight of the balloon and its contents it will be buoyant and will ascend.
yes
yes
Objects are more buoyant in water than in air.
Any thing from people to ships are more buoyant in freshwater than in saltwater. Buoyancy is determined by the downward and upward force of an object. Also, saltwater weighs more than freshwater, so objects are more buoyant in the heavier water.