UWZane

Thanks @Chris Ross for your thoughts, you're correct the Nauticam trigger relies on the small centre pin only for contact. My next through was to lay some thin layers of tape on the underside so it slots in more firmly (hopefully without raising the pin away from its seat too far). Will test and share results in a few days

Yes Sydney based these days https://www.instagram.com/zane.botany/

Thanks TimG! Getting ready for a Fiji trip in a few weeks, having some flash trigger issues, have posted in another thread. Looking forward to being a part of this newish group!

@ChipBPhoto Did you ultimately find a cause for this issue? I've been having similar intermittent non-firing with my rig when underwater, Sony A7R2 with Nauticam flash trigger and housing. After extensive trouble shooting I feel I may be able to rule out faulty cable, flash trigger, improper setup. The higher probability causes appear to be hotshoe connection and shutter button depression variance. The Nauticam flash trigger (and UW Techniques from what I can see) does not screw down into its seat as a normal land flash does, even when pushed all the way forward it can wiggle left and right slightly. Possibly enough to affect a positive contact? I'm not sure, but would be nice if these did lock into place more firmly. When testing the flash trigger on land I can get it to not fire by pressing the shutter in different ways and at different speeds e.g. will occasionally not fire if pressed quickly and hard (not half pressing for focus first), Sometimes will not fire if depressed slowly as well. Never consistent frustratingly. Are there any shutter settings I might be overlooking here?

Long time diver, ex-guide Sipadan, Komodo, now dive only for fun and photography! Sony A7Rii + Nauticam