Can anyone ID this piece of kit?

[super56r]

Hi all,

Just cleaning up an old sharkcat I bought and found this in the port sponson. There are no wires or pipes going to it and I can't see that it goes through the hull.
There's a ring next to it where it looks like there was another one fitted previously with no holes in the glass.
Is it just a decommissioned bilge pump? Seems odd as it would need 10 of them for the individual compartments.
Thanks in advance.
Wayne.

https://uploads.tapatalk-cdn.com/20170608/0ce94f57cefc81062a92b157b2ef17cb.jpg

https://uploads.tapatalk-cdn.com/20170608/0568e8114d13ac92292c3a365b169a56.jpg



Sent from my iPhone using Ausfish mobile app (http://r.tapatalk.com/byo?rid=91595)

[scottar]

Old wetbox for a transducer by the look of it.

[banksmister]

Yep old style 100mm pvc screw on cap attached to a pvc socket.
Try unscrewing the top off.

[BigE]

transducer wet box probably have olive oil or trans fluid in it.

BigE

[scottar]

At a guess, they tried the location where one has been removed and it didn't work so they moved it to it's current location but still weren't happy so they abandoned the wetbox method for another option.