Underwater camera on an autonomous sailboat?

camera

#1

I am building an autonomous sailboat that will attempt to cross the Atlantic Ocean, and I plan to add an underwater camera. I think this is the right forum to ask for your opinions.

I have already built one (and it’s likely lost in the ocean) that has an onboard camera.

The camera records for 30 seconds every hour. I am limited by the 128 GB flash memory, and not by the power consumption which is actually very low on average. I am thinking about adding another camera that would take a video of the underwater world.

• Do you think I have a chance of catching anything interesting on a 20-40-hour video in the middle of the Atlantic? Whales, sharks or dolphins would be really cool! Krakens, mermaids and unicorns too.

• What is the best place to locate the camera? In front of the boat, or in the back? Some fish may follow the boat. However, some might be scared by it. The camera body will be inside the hull so the camera won’t increase drag in either case.

Any feedback about this issue or about anything else on the boat would be most appreciated and welcomely received!

My project website is www.opentransat.com


#2

What an exciting project! Good luck with it all Andy. I’ll be watching your progress.
Cheers
Andrew


#3

I suspect keeping the underwater lens clean for weeks, months, or longer will be a problem. Do you have any idea how much and what types of marine growth are building up on the bottom of your little boat? I know of an electrochemical technique that might be ideal based on United States Patent US9371243. If you want the patentese translated to English I can help.


#4

That’s a really good point. I see there are some mechanical solutions like wiping the lens with a brush, but it adds complexity. Also there are antifouling paints, but I have doubts that they will protect the lens for weeks or months. Another solution is ultrasonic technology. I think I will just try some kind of coating first and I will see how long it will do the job. This year, there are new scientific publications about surfaces that prevent marine growth. I think it’s just the matter of time till better products enter the market. First, I need to focus on crossing the ocean and forget the fancy stuff that consumes more than 10 mA on average. The camera itself consumes only 5 mA on average.


#5

Our electrochemical process typically takes about 100mA for 10 minutes once a day. An average of under 1mA. It can also be shut off if not needed and boosted higher if conditions get severe, all under software control. In a very small nutshell, if you put electricity through seawater with proper electrodes you can get hydrogen and chlorine at the electrodes. With proper geometry the chlorine can be used to keep the lens clean. There are no residual toxins and the dosing can be timed for the convenience of the host.


#6

Thanks, that sounds promising! It reminds me making hydrogen almost every day when I was a child and the chlorine was a nasty byproduct. Pretty confident with this solution, I am definitely going to try it.


#7

I have found a research paper which is older than the patent:
https://www.researchgate.net/publication/7031344_Development_of_an_electrochemical_antifouling_system_for_seawater_cooling_pipelines_of_power_plants_using_titanium

What is the difference between this and the 1st patent claim?


#8

It is interesting how that paper differs from our method Theirs:“Using titanium as the electrode material, chlorine and hypochlorite are not generated.” while we use a titanium substrate with a multi layer oxide finish to promote chlorine generation as opposed to oxygen, calcium, manganese, and a variety of other components of seawater.

A lot of people have tried to use electrolysis to stop biofouling in the past. The bulk of our work has been in avoiding unwanted electrolysis byproducts, controlling the dispersal of the chlorine both as free gas and as hypochlorous acid film, and correlating the electrolysis with the biofilm life cycle. All of these help to reduce the electrical power requirements and extend electrode life.


#9

Do you have any idea how fast your craft will be traveling? If it is moving fast enough, fouling may not be as big an issue as you think. “Ablative” anti-fouling paint can be used that will “self polish” as the boat is sailing. Otherwise, if your craft is moving slowly, fouling could become an issue.

I’ve crossed oceans on racing sailboats that had a “kelp window”, a small plexiglass window in the hull that allowed you to look at the keel while underway. You also may not see as much wildlife as you are probably hoping to see. Once you’ve left the coast, the oceans largely seem like a vast “desert” of salt water. Every once in a while we’d have dolphins and pilot whales playing in our bow wake, or squid attracted to our deck lights at night, but other than that, we rarely saw any marine animals of any sort while mid ocean.


#10

The speed depends much on the weather conditions. It’s hard to estimate before I actually build the boat. I guess that I won’t see much, but it’s worth trying. I will record a 20-40-hour video and then I will let a software recognize any moving objects. When you are sailing, I assume you are not constantly focused on the underwater life for many hours. In the future, I would add an ultrasonic sensor or a low-power camera and it will start recording whenever something moves in front of the camera. This way, I can record every moving object during a three month journey.


#11

On the other hand, stationary floating objects do eventually attract wildlife. People stranded on liferafts have reportedly been able to catch fish and I know the mid ocean weather buoys create their own microcosm of marine life and fish over time. Rather than video, perhaps a camera that captures a frame every few minutes or hours?


#12

It’s very best project.