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Deep sea Sixgill shark on a 400m shoestring!

Check out this creepy deep sea monster! A prehistoric, 4.75m long Sixgill shark down at 280m deep, 2 nights ago, just 700m from the jetty here in Flyingfish cove, Christmas Island! I can’t believe I can just kayak out 5 minutes from shore and lower my super-simple deep-sea camera setup SO deep and find SUCH amazing animals that you’d normally need a mid-ocean, offshore research platform to study! Yet another reason this island is so amazing!

The basic setup: Two of the Blue Robotics 3" aluminium watertight enclosures, with an aluminium endcap on one end and an acrylic end cap on the other (one flat, which I stuck a torch in, the other domed, for a little GoPro Session camera, attached to a USB battery bank to give 3hrs+ and mounted just with some rubber wedges to prevent the overheating issues I had when it was snuggly wedged in a foam mount), both mounted on an aluminium rail to keep them seperate, some dive weights tied to one end (using string that’s easy to break if it got snagged) and then 400m of 3mm venetian blind cord / shoestring up to a float on the other end. On the kayak I have this 400m of cord wound onto a cheap garden hose reel. Dangle a tuna head out on front of it (attached just via a bit of thread), then kayak out, drop it down, easy. If only pulling it back up again was just as easy. Haha. =)

After 6min of free-fall it hit the bottom, 4min later the first of many Cutthroat eels turned up and started savaging the bait, and after 28min bottom time this huge sixgill shark cruised in and ate it!

Next time, 400m!!! Thanks to the great team at Blue Robotics for making this kind of top quality, affordable gear that can open up deep sea exploration to hobbyists and enthusiasts like me, literally with a shoestring budget!!! =)

Images of the setup and a video of the shark etc is on my Facebook post here (https://www.facebook.com/chrisbray.net/posts/10158453507735115), seems i’m only allowed to upload one photo here, so I left it as the shark!

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Amazing, @chrisbray!!! I’m so stoked on this. Thanks for sharing! Would you mind if we shared with our community on our socials? I know everyone will share the excitement that we all have here!

This is really cool Chris. Love the images.

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Absolutely, it would be my pleasure, thanks!

Nice setup! I’ve been working on a similar system using the 2" series enclosure to record video of motion events. Thanks for sharing, it’s exciting to see what other folks are putting together.

Hi Alex! Thanks. How have you detected the motion events? An underwater ‘camera trap’ that I could leave to just record pic/video when something’s detected passing by is something i’ve wanted to make for a while…

I have been using a Raspberry Pi (Zero W model) running PiKrellCam and powered from a USB power bank. I wanted just what you described - an underwater “camera trap”. The whole setup has a runtime of about 19-20 hours nowadays, and it’s worked pretty well so far:

I should really do a full writeup about the whole thing and share more images here at some point, because it’s been the jankiest setup for a while now (almost entirely recycled items that were just lying around), but I’ve been slowly upgrading it. To that end, the new BR 2" locking enclosure series has been a great step forward. I’ve been overall looking towards a more streamlined arrangement, and yours is pretty darn close to what I’ve settled on and am working on now - so I’m excited to see that it functioned so well!

Hi Alex! Very cool. So yours is basically always-on, analysing the video feed to check for something passing by, and if so, it saves the video (perhaps with a few seconds rolling buffer so it’s not already half gone by the time it triggers? That would be cool!) and you’re using ambient light, or do you have a powered light? 20hrs is cool… I checked when I bought it that my 3" waterproof tube cab fit a Raspberry Pi so I had ideas to try something similar. I’d love to be using it a depth though, so no ambient light, and so torch would have to be always on (or at least be pulsing on and off) and I guess the light is actually what would help attract things at depth anyway… so problem quickly becomes powering the torch, but I guess should be possible just with a big enough usb battery bank… Hard to find a torch with a wide enough beam… Anyway… good stuff! I have played with Arduinos but never a Raspberry pie yet…

Indeed, the light source is my main issue at the moment. My current solution is using a trio of dive lights rated to 300m with ~20 hours of usable battery life (there’s an aluminum version I’m eyeballing that’s rated to 600m). As you note however, it is “hard to find a torch with a wide enough beam”, and the light I have is a pretty narrow beam. I have considered fitting a non-waterproof lights into a BR housing ,as you did with your project, but battery life and brightness is a big hurdle I’m trying to clear in that area.