DocVikingo once bubbled...
Edited piece from my "Dive Workshop" column in Jul '00 issue of "Rodale's Scuba Diving":
"What safety devices should I carry? Tom Douglas, Santa Fe, NM.
I am a firm believer in safety devices, and recommend that you carry devices which emit auditory and visual signals, and can be used both day & night. Fortunately, there are good quality devices of both varieties readily available at reasonable cost. At a minimum, these would include:
1. Safety sausage/signaling marker buoy.
2. Dive Alert with back up whistle.
3. Strobe. .
Other safety devices include a signaling mirror.
I highly recommend carrying both visual (for both day & night) & auditory devices. You'll be unimaginably glad you do if you ever need them."
Best regards.
DocVikingo