Dive lights started as tools for low-light situations but now serve as essential equipment for all dives regardless of water brightness. The equipment serves multiple purposes beyond night dives and cave and wreck exploration because divers use it for communication and to inspect spaces under rocks and corals and to record underwater footage.
All dive lights function as communication tools in addition to their primary purpose of illumination. Three primary dive light signals are used:
- The OK signal consists of a slow circular motion that matches the hand signal pattern.
- The attention signal requires divers to move their light beam in a gradual vertical pattern toward their teammates before adding additional hand signals to deliver the message.
- The out-of-gas signal requires a fast horizontal side-to-side motion which serves to create an urgent visual warning.
The beam should stay steady and point forward when you are not signaling to prevent confusion with regular operations. The light beam should move at a slow pace to prevent mistaken interpretation as an emergency signal and always avoid directing the light into the eyes of other divers. Direct the light beam toward the area where your teammate should see it when they are not facing you. Briefly direct the light at your teammate's face to alert them before stopping the beam to prevent eye damage.
A single light source works well for all daytime open-water diving operations. Each diver needs to bring three lights when diving in overhead spaces or at night since they must have a primary dive light and two backup dive lights. The lights need to be reachable with both hands since storing them in one-sided pockets is not recommended. The Goodman handle on a primary light provides the best option because it maintains light attachment to your hand while enabling you to perform other tasks. The setup enables divers to light up areas in front of them or below them when using specific attachments which proves helpful for tasks like writing on wet notes.
Each diver needs to track their light battery duration before starting their dive plan. The failure of equipment during dives requires divers to learn effective backup light usage. When your primary dive light fails you should activate the backup light while it remains attached to your shoulder D-ring for quick access. Signal your team members before you move to the backup light. The Goodman handle enables you to maintain your primary light on your hand while attaching the backup light for instant transition. The lack of a handle requires you to hold the light with one hand which restricts your ability to perform other tasks. The backup light should be secured to your wrist using a bungee cord or you should attach its bolt snap to your compass bungee to stop it from falling during emergencies. Some exposure suits include wrist slots which serve as light holders.
Divers typically save their lights for dark conditions yet these tools provide substantial benefits during daytime open-water dives. The light provides better visibility in dark areas while serving as a distress signal when you become lost at sea during sunset. The beam from a dive light allows distant communication since it remains visible even when divers are out of sight. When you lose contact with your team follow the standard procedure by scanning your area for one minute while moving your light in a vertical pattern to increase your visibility for teammates who are far away.
Conclusion
The evolution of dive lights has transformed them from basic underwater illumination tools into vital instruments which serve multiple functions for safety and communication and exploration in all diving situations. The importance of dive lights reaches beyond their original purpose of night diving and overhead exploration because they provide essential functions for underwater communication and visibility improvement in all water conditions.