help selecting light please! (go for 10w canister???)

[bradshsi]

A 21 Watt HID will do the job or just maybe overvolted 50 watt Halogen.

The only way to get a 21 Watt HID for under $300 is to buy a (winning) lottery ticket.

OTOH if your husband is so inclined the Halogen can be built for less than that amount, but it's not an option for most people.

Good luck.

 

[ronrosa]

2 of your requirements spell halogen all the way. $300 and ability to turn on/off instantly.

 

[bradshsi]

2 of your requirements spell halogen all the way. $300 and ability to turn on/off instantly.

Good point. I'd missed the instant on part of the OP. HID's have many good attributes but quick on is not one of them. Plus it wrecks your HID bulb life.

Given that IMO you have no realistic choice other than Halogen (LED's being too puny and/or too expensive).

You'll pay $460 for a Nocturnal light (I know this is above your budget, but they look very well made).

Or you could get a no name light like this from ebay for $250

You may be able to pickup a used name brand halogen like this or this or this from ebay for under $300, just don't expect the canister to be small and lightweight...

Finally if you're DIY inclined you can build your own for about $150

Hope this helps

 

[H2Andy]

one thing to consider is that if you will be diving with someone who is using a 21w,
they will barely see your 10w if you are signaling from behind.

not so bad in a cave, but awful in open water

 

[ronrosa]

I'm a fan of halogen lights. Relatively cheap, easy to replace parts, and since my main use is for shooting video, the instant on/off is a big plus on burn time and for not scaring away animal life.

If you look hard enough, you should be able to find used AUL canisters that aren't too big. My AUL is 3.5" diameter and 10" long.