Equipment

Equipment Review : Nauticam USB-C Bulkhead

by Brett Eldridge

Background

One of my favorite rectilinear lenses for underwater wreck photos is the Tamron 17-28mm. It isn’t that I don’t like fisheye lenses, but for wreck photography (which is 90+% of my photos) I really prefer the straight lines from a rectilinear lens.

Given the outside diameter of the Tamron 10-17 lens and the N100 port on the Nauticam a7rIV housing I have, it requires removing the lens from the camera body before attaching the dome.

The general process is as follows:

  1. Remove the lens from the body
  2. Insert the camera body and lock it into the housing
  3. Attach the lens to the camera body
  4. Attach the dome port
  5. Seal everything up and vacuum test.

This really isn’t an issue until you might have to do it on a rocking boat or during a rainstorm or in some other condition that is not ideal and you might want access to the USB-C port without breaking the vacuum or pulling the camera apart and out of the housing (an exposing the camera sensor).

Solution

I recently read a review by the estimable Chris Ross on Waterpixel about a bulkhead port from Nauticam that connects to the USB-C port on the camera and allows access from outside the housing (while it is sealed).

I see (at least) two specific use cases for this gadget: (1) charging the camera in between dives without breaking the seal on the housing and (2) downloading photos at the end of the dive without breaking the seal.

I decided to purchase the USB-C bulkhead (and an adapter) from Backscatter. This post will provide an overview of installing the bulkhead and how it works.

Installation

On my housing, the existing M16 port is occupied by the Nauticam vacuum valve so I had to purchase the M24-M16 adapter in addition to the M16 USB-C bulkhead so that I could install it into the unused M24 port.

The installation process involves

  1. Removing the M24 blanking cap (I put this into my camera spares kit that I take on trips in case I need to remove the USB-C port).
  2. Attaching the M16 USB-C Adapter to the M16-M24 Adapter
  3. Installing the assembly into the housing

You should make sure to use some o-ring lubricant when assembling the pieces. Below are some various photos of the parts and what it looks like when assembled

Additional Installation Notes

Note: It is really important to ensure that the cap is on the bulkhead when it is underwater.

Water (and saltwater especially) is not very friendly for cable adapter ports. I don’t think it would harm the camera or allow water into the housing if you left the cap off, but it would probably ruin the bulkhead adapter USB-C port.

Similar to the cap for the vacuum port, I attached a small sticker and some cave line and tied it to the left handle arm to make sure it doesn’t go missing and to hopefully help me remember to attach it before diving.

In addition, as you can see above the lower left photo, I have an extra post installed with a 1″ ball mount for attaching a GoPro camera or Focus Light. I had that installed on the left side of the housing. With the USB-C port and adapter installed, that is no longer a viable position and I needed to move it to the right side.

This was, unexpectedly, the most complicated part of the whole process.

There is an “insert” that goes into the housing so that an allen bolt can be used to secure the handle. When you use a post for a 1″ ball mount with a M10 bolt, that insert is removed.

I needed to remove the insert from the right side and install the previously unused insert on the left. I had previously cranked down on the allen bolt on the right side and the insert would just not unscrew. I tried three different types of adjustable spanner wrenches and none of them would get it to budge.

I’ve tried these three different tools:

None of them got it to budget. So, I sent the housing to Nauticam. They couldn’t get the insert to budge either. They said they could try to remove it but it might damage the housing and that would be a very expensive exercise. Instead, they recommend I just simply leave it and buy a 1″ ball mount with a M5 screw instead of M10. I didn’t even know those existed. 🙂

That specific part even has a small flange that locks it into the handle bracket and prevents it from rotating.

Results

I haven’t had a chance to test the system “live” in the field yet; however, my testing at home and on my workbench is promising. I can easily leave the unit vacuum sealed and charge the camera and also download photos.

Obviously, the first aspect of charging the camera while in the housing is pretty easy and straightforward.

Given the amount of photos I take during photogrammetry projects, it will be interesting to see how slow (or fast) photo downloads will be over USB-C to a laptop. Until now, I have removed the memory card(s) from the camera and plugged them directly into the laptop to transfer photos. My initial quick testing indicates that it will be slower over USB-C but I will do further testing.

[I recently did a couple small photogrammetry projects and downloading both the RAW and JPG photos was a little slower but worked well].

Disclaimers

I am not sponsored by anybody. I pay full retail price for all of my cameras, lenses, housings, etc.

Not a single word of this post was written by AI.

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