400 ft down, great vis & light

[skeet]

Mysteries of the deep documentary about the Britannic shows divers down at 400ft and the video is great with all the natural light. I couldn't believe and hadn't heard of there being light down that deep. My diving lake has very little light at 30ft right now. I have so much good diving still to be exposed to.

 

[DA Aquamaster]

In my admittedly limited experience, if you have a decent video camera with a fast ISO setting and a fast enough lens with a big enough aperture, things will often look a lot brighter on video than they do to the unaided eye in natural light conditions at depth.

 

[rab]

I read that the theoretical visibility limit in distilled water was something like 242ft. If that's true, how do you get any natural light 50% beyond that?

-Rob

 

[Deep Sea Alan]

Hello Skeet,

I have seen enough natural light at 175’ at San Clemente Island (off California), that you did not need a light and 0 natural light on a 300’ HeO2 Hard Hat Dive off Key West Florida. I don’t recall the actual depth when it really started to go dark but I believe it was just passed 200’, (base on the time it took me to get down to the stage with the other 2 divers). Maybe some of the Tech/ Military/ Commercial divers reading this thread could “shed some light” for us. What is the deepest you have been and still had natural light? Please tell us where you were at the time. Regards


Alan

 

[skeet]

Have no idea myself but thought it to be misinformation or really magnificent.

 

[matt_unique]

I believe Curt Bowen has done this depth with video or camera. What kind of vis and where?

tx

--Matt

 

[skeet]

I think it was the Aegean Sea, vis was 60-100ft maybe.

 

[medic_diver45]

Edited- see below

 

[medic_diver45]

Here are some photos of the wreck....seems like really, really good light.....if it's four hundred plus feet down, just let me say WOW....my ears hurt just thinking about that kind of depth.....
http://website.lineone.net/~britannic98/photo.htm
http://website.lineone.net/~britannic98/photogal/bow_area.htm

"She lies on her side in only 350 feet of water. So shallow, that the bow hit bottom before she totally sank and with the weight, the entire bow is now bent. She was discovered in 1976 on an Underwater Exploration by Jacques Cousteau. She is largely intact except for the massive hole in her forward bow. The hull below the Shelter Deck is completely blown away between holds 2 and 3. The hull sections of the keel are simply missing for a distance of about 60 to 70 feet. The port side hull plates are bent outward, indicating a large explosion from within, probably from ignition of coal dust in the reserve bunker." SOURCE: http://www.webtitanic.net/frameBritannica.html

"HMHS Britannic sank in about 400 feet of water..." SOURCE: http://www.lostliners.com/Liners/White_Star/Britannic/index.html (The www.lostliners.com site seems to be pretty interesting just because of the number of wrecks it covers).

 

[JeffG]

I thought the Brittanic footage was done with some sort of overhead suspended light platform in order to light a good portion (if not all) of the ship evenly. Or am I confused....I remember hearing about the program that is the focus of this thread, but unfortunately did not get to see it on TV.

Here's some more info I dug up on the Brittanic (in case anyone cares):
http://www.ecophotoexplorers.com/discovery.asp#britannic

They did that for the Titanic...that could be what you are thinking of. The one guy I know that did the Brittanic used dual 18W HID lamps.

He did say that the vis was so good one day...he could see the wreck when he was at ~125 ft.