| Rob,
The idea of the back up, is just that a back up. The primary goes and you call the dive. Diving in the Northeast and New England, we have viz is the 2 ft (totally crappy) to 30 foot. Sometimes very dark water. If your primary light goes, you pull out the back up, fire it up and your team can end the dive if it is agreed upon. You would put the OOL (out of light) diver in between the two divers with functioning primarys and continue the dive or abort.
The back up is not meant to be a replacment for the primary, but to give you some light. LEDs are really cool - they are something that are going to make the BU lights better, but if cash is tight, two BU first and the LED down the road. LEDs are more of a "want" than a "need".
Just my two cents. |