Final answer:
The described entry method during a dive briefing where divers enter and descend as a group immediately is called a negative buoyancy entry or negative entry.
Step-by-step explanation:
DURING THE DIVE BRIEFING ON THE BOAT, THE DIVEMASTER DESCRIBES THE ENTRY TECHNIQUE IN WHICH ALL DIVERS ENTER THE WATER TOGETHER AND DESCEND AS A GROUP IMMEDIATELY, WITH NO TIME ON THE SURFACE. This method is essential when needing to reach a specific location underwater directly from the boat. This type of entry, where divers enter the water and immediately begin their descent, is referred to as a negative buoyancy entry or a negative entry. It is used in situations where there might be strong currents or a need to quickly reach an underwater formation such as a pinnacle before drifting to the main wall, as described in the scenario. When performing a negative entry, divers often release the air from their buoyancy compensators to achieve negative buoyancy to sink right away when they enter the water. The use of a negative entry ensures that the group stays together from the moment they enter the water, descending directly to the target depth or location without being dispersed by surface conditions. Divers must be aware of buoyancy control and pressure equalization throughout the dive to manage the risks associated with pressurized gases in the body and to prevent unwanted buoyancy changes, as indicated by the reference information.