Water entries with camera gear

I've done a lot of thinking and research when I was buying it, but in the end I went with 180° one. Mainly just because I do a lot of verticals and simply didn't want to bother rotating the viewfinder each time I switch the orientation. I doesn't bother me much for macro, because usually I don't have any problems getting low.

I also did backrolls with it and there was no problem. I made sure that I had enough room on the boat before rolling in to prevent accidental bumping with other divers, left the port cover on, clipped the housing on the chest D-ring, held it as far away from me as possible and rolled in. I'd be more worried about damaging the dome than the viewfinder. It's (at least Nauticam's) pretty robust

19 hours ago, ChrisRoss said:

I can see why backward roll entries are done but I've always thought they can't be the only option for starting a drift dive, for example why can't the people with cameras hang on to the side of the boat and all let go together, guess it depends on the currents.

I would add I would only think of doing it with a vacuum system in use, the vacuum means the seating in force on the viewfinder will be around 5kg. 

 

Many times it is possible to hang on while the mate hands the camera down.  However current and surface swell many times make this impractical.  I was wondering what force the vacuum would create on the viewfinder.  5kg is substantial.

11 hours ago, Andrej Oblak said:

I also did backrolls with it and there was no problem. I made sure that I had enough room on the boat before rolling in to prevent accidental bumping with other divers, left the port cover on, clipped the housing on the chest D-ring, held it as far away from me as possible and rolled in. I'd be more worried about damaging the dome than the viewfinder. It's (at least Nauticam's) pretty robust

I do the same on a backroll, except I hug the camera with one hand, dome to chest, and place one hand over my reg.  My mask strap is always inside my hooded vest.

I'm curious, why do you hold the camera away from you?

8 hours ago, Redwing said:

Many times it is possible to hang on while the mate hands the camera down.  However current and surface swell many times make this impractical.  I was wondering what force the vacuum would create on the viewfinder.  5kg is substantial.

I just checked my numbers again and the closing force is closer to 2 kg on the surface - what you get for rushing calcs.   It will get to 5kg closing force by about 6.6m depth.  This assumes 200 mBar vacuum, in the housing and a 27 mm diameter viewfinder adapter. 

The force goes up as the diameter of the seal increases, so an N120 port has a closing force of 23kg for example.

When I need to roll or jump with a camera, I start with the camera close to me and as I hit the water push the camera upwards. I try to keep the back of the housing (and hence viewfinder) down and port upwards. I always have a lanyard attached.

My theory is

• This reduces the speed the camera hits the water
• I create a hole in the water the camera follows me into
• Nothing on the camera bumps bits of my kit in the process
• No o-rings or joins are subject to a lateral force of water

Whether the above is valid or just a rationalisation, I have never had a camera mishap doing such. On the other hand, I have come close to losing cameras when they are passed down from the boat.

I have jumped from 3m from a small cliff into the water with my housing (vaccumed) + acrylic dome in my hand. They can definitely take a beating!

Sorry, going completely off-topic..

15 hours ago, Redwing said:

I'm curious, why do you hold the camera away from you?

Similar as @JohnLiddiard said 2 posts above: I believe that by doing this I reduce the stress on the housing. I break the surface with my tanks and my body, then camera just follows me and doesn't directly impact the water. And usually I'll have spare reg dangling around my neck, main and backup lights, stage tanks, spools, etc. clipped on chest D-rings and if I hold the housing away from my body, there's less chance of any of those items hitting it or the dome port.

On 1/27/2022 at 8:48 AM, Andrej Oblak said:

Similar as @JohnLiddiard said 2 posts above: I believe that by doing this I reduce the stress on the housing. I break the surface with my tanks and my body, then camera just follows me and doesn't directly impact the water. And usually I'll have spare reg dangling around my neck, main and backup lights, stage tanks, spools, etc. clipped on chest D-rings and if I hold the housing away from my body, there's less chance of any of those items hitting it or the dome port.

I'm with you and @JohnLiddiard all the way down with one clarification.  When you execute a backward entry do you complete an underwater flip?  Or do you somehow arrest your rotation and just sink back first with your camera following you down?

When I backward roll without my camera I go ass over teakettle so I can quickly surface heads up and grab the camera from the mate. 

If I were to hold my camera at arms length and execute a complete roll I'd be subjecting the entire camera to a significant lateral force.  I avoid contact with my gear and camera by entering with my neoprene cover on the dome.  We apparently dive a similar configuration.

The mechanical design of the Nauticam Viewfinder caused me to reconsider my entry method and I apologize for hijacking the previous thread.

51 minutes ago, Redwing said:

apologize for hijacking the previous thread.

Not a problem, don’t worry. It’s an interesting and worthwhile discussion. 

12 hours ago, Redwing said:

I'm with you and @JohnLiddiard all the way down with one clarification.  When you execute a backward entry do you complete an underwater flip?  Or do you somehow arrest your rotation and just sink back first with your camera following you down?

When rolling off the boat, the objective is for my cylinder/back to hit the water first. I don't think I ever finish a lengthways roll once in the water. Stretch out and twist is always an easier maneuver.

I only extend my arms as I hit the water, so my body goes down to arms length while my camera is level with the surface, then follows me at arms length. The rest depends on the dive plan.

If the plan is to gather by the boat, I usually do a couple of quick kicks down backward and away to make sure some muppet doesn't roll on top of me or my camera. Then surface a body length or two away from the boat and wait, or swim to the grab line away from where others could roll or jump.

If its a straight down and rendezvous on the seabed, I stretch and twist to face down and keep on kicking.

A lateral force once underwater is negligible. Its a lateral force, or any force, at time of impact that I strive to avoid.

Better insight might be gained from understanding when housing systems have failed during water entry. I expect you'd find very few even anecdotal reports.

To me or seems aluminium housings are built like tanks and ports under vacuum are sealed tight.

I'm more concerned about avoiding entry techniques that resulted in the photography equipment hitting myself of dive equipment.