Thru-hull sensor size

[aaronaxvig]

I am ordering a replacement thru-hull sensor for our Hunter 376 and they offer 43mm and 52mm size sensors. The existing sensors are presumably the stock ones.

In the attached picture the tape measure was a little closer to the camera so the grey threads sticking out of the grey nut are actually 2 inches in diameter, even though they look a little smaller. 2 inches equals 51mm so I think the 52mm instruments would the right ones?

Or maybe the grey threads are an adapter and the black plastic innards would screw out to make a 43mm hole?

Also I believe I read a post on here which mentioned that the stock sensors had a threadlocking compound applied so they were basically not removable. Do I have that to look forward to?

Thanks for any advice!

 

[907Juice]

I may make some enemies on this one... Unless it is a paddle wheel or something that MUST be in the water, most will work if you glue it to the bottom with a toilet wax ring. I haven’t replaced any on my new boat, but I never had any problems on a previous boat.

 

[aaronaxvig]

Following up...I ended up ordering the 43mm ones and they were the wrong size. So I ordered the 53mm one which actually includes the paddlewheel, depth, and temperature all in one unit...cheaper than filling and redoing the holes and better to have the fiberglass left original. I rebedded one of the old units in the starboard hole and installed the new one (Airmar DST800) in the port hole.

The wires for the old ones ran back to near the rudder and then up to the binnacle from there. I ran my new NMEA2000 wire to behind the panel at the left of the nav station, where I have 1/2 of my NMEA2000 drops. I also have a NMEA2000 backbone run through the conduit from above the nav station to the port lazarette, and then from there into the binnacle where there are the rest of the drops for 4" displays and chart plotter.