PADI Divemaster Certification Practice Exam

How can you make an object more positively buoyant?

1. Decrease the weight only

2. Increase both weight and displacement

3. Lower the weight or increase the displacement

4. Increase weight significantly

The correct answer is: Lower the weight or increase the displacement

To make an object more positively buoyant, lowering the weight or increasing the displacement is key. Buoyancy is influenced by an object's weight and the volume of water it displaces. An object is positively buoyant when it displaces a volume of water that weighs more than the object itself. When you lower the weight of the object, you reduce the force pulling it down, making it easier for the buoyant force generated by the water to lift it. Similarly, increasing the displacement—by altering the shape of the object to move more water out of the way—means that the upward buoyant force is greater. This principle aligns with Archimedes' principle, which states that the buoyant force on an object is equal to the weight of the fluid displaced by the object. Therefore, adjusting either weight or displacement positively affects buoyancy. Increasing weight significantly would actually produce the opposite effect, making it harder for the object to float, while increasing both weight and displacement simultaneously doesn’t guarantee that the object will become positively buoyant; buoyancy depends on the net effect of the changes.