Retaining Clips on Thrust Motors


Hello All,

Is there a reason why the retaining clips are left off the two motors that serve as the horizontal thrusters ? It seems like there is a possibility of the motors pulling out of the casings in reverse.



Hello Jon,

We have tested the horizontal motors and have not seen an issue with the horizontal propellers pulling off the motors. The reason they are left off is so that the bells can be pulled off the motors by hand in order to dry and clean them in order to help protect them from corrosion. The vertical propeller with the two blades has significantly more thrust than the ones with three blades and does come partway off when running the ROV on setting 5 which is why the retaining clip is put on.

If you are having issues with the horizontal bells pulling off please let us know as this would be a new problem.



My vertical thruster has the same prop as the horizontals, and I don’t remember seeing in the instructions to put the clip back on. I seem to remember being told to discard them all. My kit was shipped quite recently so I assumed I have the latest?


Hello Rick,

The change of the vertical propeller happened very recently. See this blog post for more details on the change. The change is incorporated in ROVs with a serial number of 1400 and above. The directions were updated to reflect the change. If you have an ROV with a serial number below 1400 and the three propellers all have three blades then you do not need to worry about putting the retaining clips back on the motors. They should not come off in the water and this will allow you to remove the bells on land in order to clean the motors after each dive.

Please let me know if you have more questions on this subject.



Thanks for the reply Brian. As a follow up question, how do we deal with potential corrosion on the vertical motor ?


Ok so should I consider updating to the new prop? Don’t know my kit S/N but all the props are 3 blade so I must be lower. Obviously cleaning would be a bit of an issue with the clip on but what’s the plus side? Quicker descents and ascents I assume?


Hello Rick,

Your assumption is correct. The two blade propeller does allow you to ascend and descend at a faster rate. The downside of this improvement is that it makes cleaning the ROV in order to fight corrosion more difficult.

If you are not having problems with assent and decent times with your current configuration then it is probably not necessary to update.



Hello Jon,

For now my best advice would be to run the ROV in fresh water after a dive in order to get clean water flowing through the motors. If you are seeing issues with corrosion it should be relatively easy to remove the vertical motor from the ROV and take the retaining clip off in order to take the bell off to clean.

We are working on a post dive guide on how to clean the ROV.



Haven’t had mine in the water yet so no comments re decent rates available. Still working out bugs.



The original forum post describing the new propeller and how to upgrade your ROV is here.