how deep before it gets dark?

[H2Andy]

not sure where to put this question... i figured this is the best place

if you dive deep on clear water (say the Caribbean) during daylight, how
deep do you have to go before all ambient light is gone?

i have been to 110 in the caribbean, and there was still plenty of light.
on the other hand, on a dive in 40 Fathom Grotto, all light was gone around
that same depth, and it was totally dark by 150 feet.

clearly, low vis kills all the ambient light faster than good vis. so, in good vis
(again, the Caribbean) do you know how deep you have to go before
all ambient light is gone?

thanks in advance

 

[mart1]

In clear water 450ft (150 mtr) can be still light, sort of a monochrome twilight zone.

 

[H2Andy]

wow...

that's deep

 

[JeffG]

wow...

that's deep

I know a guy that had ambient light on the Brittanic. ~400ft to the sea bed.

 

[tgarcia10]

I would probably have my eyes closed, because I was scared. It would be mighty dark. hehe.:lol:

 

[H2Andy]

no kidding, man

 

[cudachaser]

I have some collegues that pilot the Harbor Branch submersables...In clear water at 1200ft they have turned off their lights and still could surface light

 

[WaterDawg]

1000M is where the aphotic zone begins, thats where 100% of light is absorbed (60% of light is absorbed 1m below the surface and another 20% in the first 10m).

Water, creatures, salt sediment all absorb light.

 

[jcpol]

I have personally been in a submersible in the CAyman Islands to a depth of 1040 ft and still could see with ambient light. Very dim, but still visible. Do this if you EVER get a chance to.

To WaterDawg - aphotic means without light - the 1000m depth, however, is completely dependent upon water clarity. Clarity is controlled by dispersed sediment in the water column, organic material, etc. The aphotic zone in the Gulf of Mexico near the Mississippi delta is much shallower.

 

[H2Andy]

ok, well, i can safely say i wont' be diving that deep in the Caribbean

not on purpose, anyway



jcpol, i saw those submersibles when my wife and i were in Grand Cayman.
they looked fun, but i recall the price was something extraordinary, so
we decided to hang out at the Hard Rock and drink.