Lake Merritt Monsters

July 30 2016

Expedition Video

Ever since I walked over a pedestrian bridge on Oakland's Lake Merritt and saw 3ft striped bass hanging out in the flood tides, I've been fascinated what might be beneath the surface of the lake. Oakland has a goofy legendary monster called the "oak-ness" but I like to think of them as reflections of all the monsters that do live in the late. The striped bass, large bat rays, pacific pipe fish (brought up in the mouths of earred grebe's), and sea hares. Not to mention all the diving ducks, grebe's and cormorants -- all of these are monsters in the eyes of other creatures. I want to spend some time exploring this underwater landscape, and documenting more about the creatures below the surface. I know there is plenty not well about the lake -- with a tremendous amount of trash finding it's way into it, but even that will be interesting to document. Read background

July 30 2016


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Mission Underway

Finally got out into the wild again. And ... learned some more lessons!

  • The first thing that went awry was on the top side communication box. Putting the wires the little box that has the springs to hold the wires in fell apart. After a moment of despair, I settled in to getting back into working order, and succeeded. Though, I'll have to work out some way to keep it in place... One could easily drop a piece in the wrong place.
  • *My tether management system. * Turns out I hadn't quite thought it all the way through, and I'd not actually tested it. I ended up laying out a length and just seeing how far I got. Once I got it home, I did a little reworking of my winder and I think have it in a good place again.
  • *Control direction. * My controller is working in the exact opposite way that feels natural so it was difficult to feel I was getting anywhere. I later realized I could have just turned it upside down and been happy, but I ought to figure out how to adjust the code for that. Testing it is a bit of a pain though, so almost might as well just leave it as is.
  • Tether+rocks=bad Luckily due to my earlier constraints I did not get very far, but rocks, even small ones were proving problematic. My next test, I'll have to pick an area a little more devoid of rocks. But having better control will at least allow me to go back. Also having someone doing a little bit more tether management with me would be useful.
  • * Scummy water * makes for crummy visibility! Be careful where one drops the rover in, I guess! (another negative for Lake Merritt perhaps given concentrated run off)
  • *Vertical Engine trouble * The biggest downside to my run -- my vertical engine was working fine for about 10 minutes then decided to stop working. Can't quite tell what went on here, it was working fine when I got it home again after cleaning, so maybe it was just jammed by a little piece of debris.

More soon.

Back at the lab, been doing work troubleshooting my engines... One of my engines wasn't working right. Support suggested I update all the software and firmware and all that goodness in case there was something buggy. For good measure, I ordered some new engines along with SD card with the latest and greatest.

The update process was less fraught than I expected, and I had the ROV back up and running pretty quickly. But alas it was to no avail, so I began the slightly tricker task of replacing the motor.

In stripping wires, I managed to to rip one wire off of one engine -- luckily the order comes with a couple to spare. I much more carefully stripped the wires down and set up to solder the engine on.

The starboard engine has the shortest wires, so the least slack to work with. Which was problematic because with my now rusty soldering skills, I managed to blow it on one connection (soldering quickly on those wires is important, because it's easy to overheat the wires and melt the plastic sheathing -- or, as it turned out in my case, one end of the plastic shrink tube that was to protect the connection).

But it's on and back in place. And to my relief, the engine sounds more or less the same as the other -- so hopefully I'll be running in straight lines from here on out.

I still can't tell why the original motor was bad. It doesn't appear to have any defects or anything stuck inside, so who knows.

Now, I just need the rain to clear up a bit -- and I'll be out on the lake.

This has been fun to read! I hope you get a chance to re-visit the mysteries of the Lake Merritt abyss

Well my first run at the lake did not go all that well. The run was short and not straight for a variety of reasons, and I've not yet returned to the water. The most interesting thing natural history wise that happened was having a juvenile western gull become interested in the ROV.

First problem -- learning that i should have figure out the umbilical before I went out to the water. The process of unwinding the cable took nearly a full hour of painful work and nearly drove my help (a kind and gracious friend) mad. I thought it was going to be a simple task. It was not. Subsequently, I found a device for wrapping up cords that I think will serve me well in the future.

Second problem -- the rover wouldn't go straight. I've not been able to diagnose this problem as of yet, but hope to spend a bit more time on it this week.

Third problem -- the rover wouldn't dive. I think this was simply a matter of weight. It is salty water, so I need to add some more ballast. Which I hope will be easy.

Fourth problem -- it nearly burst open, the electronics chamber. Subsequently I learned that the electronics heat up the air in the chamber and expand it, putting more pressure on sides. Luckily it didn't popup outright and leaked very minimally. The two solutions seem to be either -- putting a weight on it for some hours before putting it in the water, or getting a vacuum pump and reducing the air and creating negative pressure into the chamber. The latter sounds safer, but not having one handy, I'll probably do the former.

The fifth problem was safety. I subsequently had a very negative hostile (entirely unexplained) encounter with a homeless individual which has made me wary of the area, but will likely do it anyway, just making sure to have someone with me.

The interesting thing with the channel now is that it has had another culvert removed at the 10th street bridge which will bring new changes to the lake as a whole affecting the tides. The channel was closed off for 5 days with two inflatable dams while the crews worked day and night (or so it seemed) to remove the concrete and reshape the channel.

Thanks for sharing the challenges Adrian, and glad to hear you're still at it. Keep going!

Success! My ROV is complete and AC Grebe (R 001) in the water. Things appeared to be A OK, no leaks that I could see. Motors all functional.

I did notice it seemed to turn one direction better than the other. And I'm guessing i might need a little more weight.

I also note that it would be much more intuitive to have a game controller. But I've not been able to successfully get a controller working as of yet.

By hook or by crook I am aiming at the weekend of September the 18th for an actual in the water expedition. I have several offers of help, just need to scout a good spot and find the right time (aka tide).

Hopefully in the meantime, I can figure out my controller issues.

The OpenROV bathroom tub test! Classic. I think there's a whole Youtube genre about this.

Congrats on finishing the build! As a fellow Oaklander I am always excited to see expeditions happening in Lake Merritt. Looking forward to following along!

Thanks David and Margaret. I also figured out my playstation controller problem as well. One step closer :)

Preparation Stage

Still haven't quite made it to launch just yet. I fell sick for a little while and have been struggling to find time since I've been better. And I've got one little supply I need to get before I dunk it in water -- lube for the O-Rings.

One sideline joy of this project has been working in my barn. A barn built for horses in 1908sh by an Irish butcher who ran a shop in downtown Oakland, and carried his meat around in horse wagons.

The barn is now split between two condo units, so we each have half. I usually work with the doors open, and have enjoyed the birds who come by. A California Towhee with a fledgling, some Dark-Eyed Juncos, and an Anna's Hummingbird. The hummingbird comes to feast on one of a backyard beast of a plant I have, that puts out massive cone like sets of flowers.

I was able to stand by the door and watch and get some excellent slo mo video of the hummingbird as it went about its business -- including checking me out.

I had a teacher from Oakland HS stop by. She had a bunch of Environmental Science students that wanted to follow along with your expedition.

Hey David, I think we've already been in touch... they have an old expedition ohsesa?

Success! Last night I plugged in two my computer -- and after an agonizing minute or so, the ROV blooped, and lights started shimmering on my board. It was a relief that I had not crossed any wires or the like.

It took me another minute or two to get the network properly established, and the control panel in place, and voila, there was my workshop on screen.

An hour later, I was showing it to my colleagues at Nerds For Nature at our monthly meetup night and was showing off the console and the rover. Lots of good discussion had.

I hope to finish up this week, and maybe, just maybe get it in the water on Saturday for some sea trials.

I've also been wondering, what I should christen this little vessel of electronics -- and I think I have landed on something around my favorite diving bird, the Earred Grebe: Grebee? Earov Grebe? Grebver? Grober?

I'll work it out eventually, but if you have any ideas...


Finally closing in on the completion of my ROV. I made one acyrlic gluing mistake (i had to reorder the electronics chassis), and didn't order epoxy - and wasted a good couple weeks looking in stores before i gave up.

Otherwise, the process has been quite enjoyable - and we'll soon find out how good of a job I might have done with everything else. My soldering seems better than my acyrlic gluing.

I'm lucky to have a good workspace - a barn built in 1908 for an Irish butcher's horseswho lived in Oakland.

Looking forward to having it in the water soon.

Expedition Background

Lake Merritt is not actually a lake. It is a tidal channel, where bay and east bay creeks mix, a brackish body of water. It was made a lake in 1869 when the mayor created a dam -- and over the years westerners move in and developed around it, the channel hemmed in by streets and buildings, paving over mud flats, and removing the willows and oaks that once surrounded it.

In 2013, 140 years after the original dam was built, the lake has been reborn, with the channel reopened to the tides and plans to open it even further removing obstacles further down the channel.

Those obstacles don't stop the tide and water though, and the bay slipped back into the water bringing more fish, and bat rays, and sea hares. Some months of the year you might see a flotilla of cormorants out hunting with brown pelican air support. An otter even swam about the lake one day (apparently only to move further upstream).

There are a few places you can see what is going on under the water -- cormorants, grebes, scaups, and other ducks diving, bat rays, striped bass, bait fish. Gulls commonly bring up mussels to eat, grebes can be seen snacking on pipe fish.

I would like to see what else might be going on there, or getting a different look at what can be seen from the surface. This might also turn up another ugly side of a lake surrounded and downstream from a city -- all the trash that we unleash, but hopefully that too can inform how we carry forward with the lake.


Hi Adrian, Any news? How's the build coming?

Just managed to get my toolkit together and am off on a trip today :/ so nowhere yet.

Hoping to get it built in time for the 2nd lake merrit bioblitz at the end of the month.

Hi, Adrian. Nice job. Some students from Oakland High and I have been building OpenRov's and would love to talk to you. We would especially like to meet up with you if you do any more explorations in the lake. My email is Thanks! We have an old expedition up at ohsesa in OpenExplorer.

Thanks ohsesa, I'll email ya!