Secondary depth indicators.

[northernone]

Up to a point: when all red is gone, you can tell. Though it may help to have a camera for an objective view.

I'd love a calibrated visual depth gauge... Unfortunately my colorblind tendencies spoil my red/green vision accuracy.

 

[Trace Malinowski]

I use visual references at my favorite dive sites. If without a mask, if I deploy my DSMB I have knots tied every 10 feet on the line with 2 knots at gas switches at 70 and 20 feet. Other than that, I just sense "deep" and "shallow" with light and sound.

 

[The Chairman]

What's some references you use for rough depth monitoring.

I'm with @Trace Malinowski here. When I first started diving, I used a red ribbon on my BC. The advent of me using an SPG rather than a j-valve and a depth gauge rather than that red ribbon revolutionized my diving. Now, if I notice that something is at the depth I want to be at, I will use it. Why not? Sometimes I pop a sausage and use it to float me at the right depth. Again, why not? I like to use the easy button whenever possible.

 

[AdivingBel]

For me color change depends on viz. Not so much the filtering, but the way my eyes react to the available light (I'm old and things tend to fuzz out at low light and will change how I see colors). I've been in gin clear water where feeling the extra compression on my body and muted sounds were my first clue. Also the little lizard that lives in the back of my brain popped his head up and said, "Dude, you're deep." He doesn't have a set of gauges (he can't read anyway) though as a lizard he is perceptive to colors (lizard mating rituals and all), I think he's mostly responding to other unseen (by me) factors. He is actually a very observant little guy. Though he doesn't speak up often when I dive, when he does, experience has taught me to listen.

 

[Michael Guerrero]

Hmm...if you're familiar with the site you will know various depths at different times of the year. For contingencies I have my SMB line knotted at 10ft increments down to about 50ft. That should get me most of the way out of deco in a bind. Not sure if that answers the question, but two depth gauges/computers and that and I feel comfortable I'll get out of the water unbent.

 

[JamesBon92007]

For Southern California beach diving if I'm not seeing as many fish and seaweeds etc I must be past 35-40 feet.