Night Diving

Why Do It? Night diving allows you to see different critters and or different behaviors. It is another form of limited visibility diving and some divers find their first night dive both exciting and spooky.

Learning Objectives Describe the ideal setting for a night dive. Discuss night diving techniques, including the importance of navigation during a night dive. State the minimum number of lights each diver should carry during a night dive, and explain why. Demonstrate standard light signals, and discuss light etiquette. Discuss features to be considered when selecting a dive light, including re-chargeable vs, non re-chargeable batteries.

Main Points Ideal setting Buddy techniques Communications Light etiquette Navigation Avoiding disorientation Required equipment Lighting concerns

Ideal Setting Familiar site Favorable conditions Boat

Buddy contact Good buddy techniques Positioning Plan the dive and dive the plan Personal identification lights Separation plan

Communications Light signals Diver-to-diver Diver-to-shore or boat OK Attention Distress Diver-to-diver Diver-to-shore or boat

Light Etiquette If the light is in your hand, it should be on. Don't shine your light in your buddy's eyes. Don’t shine the light in your eyes. Control the light during descent.

Navigation More important at night than during daylight Surface Use compass and range lights Make sure you can identify the exit point. Underwater Plan your pattern and stick to it. Don’t try to cover too much area.

Disorientation Most significant problem bubble trail descent/ascent line buddy bottom kelp Breathing Water in mask

Required Equipment All standard gear for daylight diving plus 2 dive lights per diver Purpose of the second light? 1 ID/marker light per diver.

Dive Lights: primary vs. backup beam pattern ease of use size purpose/function beam pattern ease of use size maintenance store with batteries out lubricate "O" rings store with pressure off "O" rings filament most vulnerable when light is on

Rechargeable Batteries Batteries die suddenly (little warning) One charge doesn't last as long as standard battery Battery Memory: If you charge battery before it is completely drained, eventually the battery won't hold a charge as long. Batteries may swell during charging, to the point that they won't fit in the light. Batteries may spike when freshly charged. Turn light on and leave it on to take the edge off. If the battery hasn’t been used in a while the first charge won’t last as long as normal.

Personal ID lights Strobe lights Chem/ID Lights: color code dive teams position for maximum visibility

Surface Lights Ranges Float or boat marker light Flashing Dressing area Be aware of background light

Have We Covered Ideal setting Buddy techniques Communications Light etiquette Navigation Avoiding disorientation Required equipment Lighting concerns

Can You Describe the ideal setting for a night dive. Discuss night diving techniques, including the importance of navigation during a night dive. State the minimum number of lights each diver should carry during a night dive, and explain why. Demonstrate standard light signals, and discuss light etiquette. Discuss features to be considered when selecting a dive light, including re-chargeable vs, non re-chargeable batteries.