Dry- or wet-mate connector with stock BR2 penetrator ho

Howdy - looking to use some form of dry- or wet-mate connectors, such as those at https://www.amronintl.com/seacon.html, with the stock BlueROV2 end caps, but im not finding matches that look perfect. Most seem to be designed around a threaded penetrator hole, for instance, with only small, optional nuts on the inside face. I suppose I could tap out the existing holes if the size was right, but we aren’t really set up to do that and keep the threading axis perfectly perpendicular, which I’m pretty sure you’d have to do to keep the outer face o-ring working …


Hi Jeff,

The standard thread for most Subconn and Seacon type “MCIL” connectors is 7/16"-20. The 10mm holes in the end-cap are actually the perfect size to be tapped for that threading, so you can use a tap like this one to make the proper threads.

A few people have done this with great results! You can use a 2-pin connector for the slim tether or for a minimal-cost setup and go all the way up to 8-pins to maintain all of the wire connections.



This will help with keeping your threads straight. I own their drill guide tool as well, very handy.

Great, thanks Rusty and Tim for the tips. Also, do you think it’d be a bad idea to try to tap out the holes in the optional acrylic end cap (on the 4" enclosures), rather than the aluminum? Seems like if we’re very careful about overtightening, and use the
nut on the opposite face, that it should work juts as well as the aluminum.

(Why do we want to do this, you ask? we’re housing antennas in the canister, so the less metal, the better, for tuning purposes)

I have no personal experience tapping acrylic but I know it can be done. Can’t tell you if it is a good idea in this application, hopefully someone else will chime in.

This is the nut I bought for my Seacons (which aren’t installed yet).


I also need a little help with this, IDK which one to choose as I want the 8 pin connectors which one is more recommended bulkhead or connector potting the cable inside a cable penetrator?.

also whats the difference between dry and wet connector? if i decide to get the connector potting the cable inside a penetrator i just need female and male plus the split scotchcast and thats all? or need anything else, with this configuration no water can get inside the connectors?


I tried potting the 8 pin pigtail into a penetrator and the wires were such a tight fit that I was not confident in the potting. I chose to go with the bulkhead instead.

You will also need a locking collar to keep the pigtail securely mated to the connector. I think this is the right one for the bulkhead fitting you posted.

hey @PacNW

Do you have pictures of your bulkhead? or the complete set you bought? like female, male, scotchcast split, locking collars, nuts etc. or maybe a previous post with this?


No pictures as I haven’t installed it all yet. I will be using the 8-pin female bulkhead same as you posted, female locking collar, male pigtail, and the 82-F1 Scotchcast kit. Search the forum, there are a few threads where people show what they have done.

I don’t have any pictures yet either but I’m using the same things that others have talked about except I am using the Male Bulkheads and Female Pigtails. I’ve got multiple 2 pin, 4 pin, and 8 pin connectors in my setup but am using the 8pin for the tether for future expansion but am currently only using 4 pins (2 for tether and 2 for GPS).

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Drew did the 8 pin male bulkhead fitted inside the 10mm Hole?

@PacNW Yes i know there are lots of topics about this but they were not using the 8 pin connector. For me I need the 8 pin connector for future expansions of the ROV.

Any pictures should help!



The bulkhead connectors need 7/16" threads. Since I needed 2 in my ROV 4" enclosure, I ended up having a custom end cap laser cut in 1/2" plexiglass. I just made large enough holes, not actually threaded holes, and then used a standard 7/16" nut on the inside. Someday I might end up going with a metal one and get a piece machined or do the tapping myself but this worked since I needed to have one cut for another tube anyway.

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Thanks! Understand now, with the 7/16" nut no leaking?

So far so good though I haven’t been more than about 3m depth yet. Real tests start Tuesday. Holds vacuum well though. There is an oring on the outside so its just like using one of the BR penetrators, just needs a little larger hole.

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Wet mate connectors expel any water as they are connected so I find them much more robust and reliable. I have seen a $4000 dry mate bulkhead and connector to a 500v power supply destroyed because a single drip of water got into the bulkhead before they were connected!