For Sale: Trident + 100m Tether + Hard Case


I’m selling my OpenROV Trident and I wanted the community to have a first swipe at it before I put it up on Ebay. It saw one fresh water use and two ocean dives off Southern California.

Comes with the following:

Trident Drone (Gen 1 motors) + Charger + All accessories (strap, ballast weights, etc)
25m Tether - Standard
100m Tether - On a spool
Hard Case with foam inserts
Original Shipping Case

Retail price: $2049.00
Sale price: $1500.00

Local pickup in Torrance, CA only. Its a bit painful for me to ship three large packages.


Hi Kevin,
Do you mind me asking why you’re selling it? Did it not meet your expectations? I wish I could buy it but I’m in the UK.


@e4andy1 The controls and maneuvering are difficult for me to use in an operational setting. Having to pitch the vehicle and drive forward to dive down is disorienting for me especially in low visibility environments and I can’t follow a marker buoy line down to my deep water wreck sites. I prefer the older 2.X kits (I had a 2.6, 2.7 and a very large custom OpenROV) where the vertical thruster would send the vehicle straight down.


Hey Kevin- Interesting to hear your feedback about following a marker buoy line. I would expect that Trident would be very good at surveying the bottom once you’re there - that’s what it’s built for - but I can understand that if you’re aiming to follow a line down quickly while pitched all the way downward that that might be a challenge. The feedback we’ve gotten from people doing benthinc surveys with Trident has been very positive, but we haven’t heard from people like you who use down lines. We’ll look into some solutions there.


Thanks Kevin. I can see the point. I have a 2.8 and I have to say that I’ve been very disappointed that it’s not easier to use. I’m sure that if I spent days in a swimming pool (don’t have access to one) getting the buoyancy just right it might work out better. It’s been in the water about 4 times in 3 years, whereas I fly my drone a couple of times a week!
I find that as it moves forwards, it nose dives and if there’s the slightest drag on the tether it won’t turn. Basically I just drive it to the bottom and hope there’s something worth looking at. The idea of going to a particular spot is pie in the sky. I had hope to do lots of research into benthic accumulation under Scottish salmon farms, which is now becoming a disgusting, filthy business, but there’s not much chance of that if you can’t even fly it where you want to go. Maybe it’s just me, perhaps it takes endless practice. Interesting to hear you have similar issues - perhaps its not just me. Thanks again and good luck with the sale. BTW, don’t ever eat Scottish salmon, it’s full of plastic, lice and chemicals!


Perhaps this will help…



You need bigger motors on your OROV2.8.

Here is a link to my OROV2.8 equipped with BR M100 motors and propellers.



I must say that I also find it very hard if you dive down in murky waters to keep the orientation of where the Trident is relative to you (the pilot). It is also very hard to pitch up and down and stay that way since it automatically want to level out after a while. This makes inspections of ship hulls from underneath, or to take a look straight down at the bottom very hard to do. I hope that the next version of the Trident have two propellers instead of one trough the hull, one in front and one in the back, Then it would be easier to pitch the Trident up and down since one of the propellers would reverse, depending on what way you want to pitch.

It would also be good to know what your timeline is for the accessories for the Trident, since that is basically the only thing that is better than the competition that is out on the market now. Most other submarine drones have brighter lights, removable batteries so you can actually bring another one and change it, in case you are in a location where you can’t charge the Trident. They also have 4K-video, wider field of view and the possibility to take photos.

I understand that you have a shitload of stuff to do, but if you want to keep the community, I think you guys need to get much better to communicate what you are doing right now, and how the future looks like etc. (most people will understand that you can’t promise stuff, but it is good to know your vision and your approximated timeline for it) :slight_smile:


In response to trouble diving to the bottom, maybe add different modes to the Stabilize flight?

Move “Stabilize flight” out of Settings and use 2 buttons on the Pilot display and Controller for Depth and/or Attitude Hold.
0-Disabled 1-Enabled
Att - Attitude, Hdg-Heading
Hold Depth Hold Attitude Description

0 0 Free flight - no stability assist
0 1 Hold Att & Hdg to when Enabled ie: Hold dive to bottom
1 0 Hold Depth, Free flight at that depth
1 1 Hold Depth, Att, Hdg ie: Transect track

Any followup from companies about transducers for acoustic location?


Way too complex for me I’m afraid.


Hey thanks TCIII I read your post with great interest. As you say, probably a major job on a completed 2.8. but I think it has to be the answer.


Am I right in thinking that they need different ESCs? Where does the extra power come from?



If you stay around a thrust level of 2, which will provide plenty of thrust, you can use the original ESCs and not overload the OROV power control system.

Here is Kevin_K’s BR modified OROV2.8. He used two T100 Thrusters and an M100 motor unlike my modification that used three M100 motor/propeller combinations.



@webhoppery - I like the direction you’re going. Using a control loop to manage attitude is exactly the approach we’ve been working on. We’ve already tested a system that holds Trident at completely vertical (either straight up or straight down) orientations, and we’ve found that to be extremely useful for diving to a known target. Since Trident is very hydrodynamic and tracks quite well, it can get through the water column quickly without being as effected by currents durring its decent, and it’s easy to pop up to the surface to see where you are once you’ve located a target. We’re still finishing up some testing with this system before we release it to our app, but in some of the field testing we’ve done, we’ve been able to dive to 60m (200ft) targets and come back to the surface in under two minuets.

Our user interface for this feature is the part we’re working on now, and the system we have found works the best is pretty simple: when you move the control stick for the vertical thruster all the way to its extreme position (either all the way forward or all the way aft) when the vehicle is pitched 75 degrees or more, it will engage the pitch controller which will point the vehicle completely vertically in that direction. For the pilot, this effectively means that if they want to dive on a certain spot, all they need to do is push all they way forward on the pitch joystick while moving forward, and the vehicle will automatically make a b-line straight for the bottom. Likewise, if you want to ascend directly upward from a given location, you can just pull all the way back on pitch while moving forward and you’ll come straight up. If the pilot eases off the vertical thruster joystick, the ROV will resume normally controlled flight.

We still have a few more edge cases to work out before this system is ready for prime-time, but I think it will be very helpful for people who are interested in visiting specific locations with Trident.

Thanks for the post!



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