Leaving expensive equipment down.

[vladimir]

why would one go down with an unattached camera if it was worth more than 99 cents?

I do it on every dive. My ~$5,000+ rig (DSLR, Subal housing, port, lens, strobes...easily over $5,000) has a tether if I need both hands free (clearing while descending on a line, for example), but I generally just hold it. Why? Because I'd like the option to discard it in an emergency. And if it ever happens, the relief of getting to the surface safely will far outweigh the disappointment of abandoning the camera. I have resolved in advance to never let a camera issue spoil a dive trip.

If you can't afford to lose it, you shouldn't be taking it underwater in the first place.

Exactly. I have the same philosophy with shirts and ties...if I can't afford to stain it, I can't afford to wear it. I keep a spare of each in my office, and if I do stain one, it's a valid excuse to buy a new one. My camera rig is getting a little bit obsolete at his point.