PADI The Aquatic Environment 4

Question 1

What is the recommended action if a diver is caught in a rip current?

Accepted Answer

Swim parallel to shore until free of the current, then return to shore

Answer

Rip currents are narrow channels; swimming parallel to shore quickly exits the current's path, after which the diver can safely swim back to shore.

Question 2

Marine organisms that are fixed to the substrate and cannot move are called:

Accepted Answer

Benthic sessile organisms

Answer

Sessile benthic organisms, such as corals, sponges, and anemones, are permanently attached to the bottom substrate and cannot relocate.

Question 3

How do upwellings benefit marine ecosystems?

Accepted Answer

They bring cold, nutrient-rich deep water to the surface, fueling productivity

Answer

Upwellings carry cold, nutrient-dense water from depth to the surface, fueling phytoplankton blooms that support entire food webs.

Question 4

When diving in freshwater versus saltwater, how does buoyancy change?

Accepted Answer

Saltwater provides more buoyancy due to its higher density

Answer

Saltwater is denser than freshwater due to dissolved salts, providing greater buoyant force, so divers typically need less weight in saltwater than in freshwater.

Question 5

Which aquatic environment type is characterized by brackish water where rivers meet the sea?

Accepted Answer

Estuary

Answer

Estuaries are coastal bodies where freshwater from rivers mixes with seawater, creating brackish, highly productive habitats with fluctuating salinity.

PADI - Professional Association of Diving Instructors Practice Test

PADI - Professional Association of Diving Instructors Practice Test

PADI The Aquatic Environment 4