Replacing depth, speed transducers?

[neilmcc]

My Hunter 336 currently has Raymarine ST (30 I think) depth and speed transducers fitted in brass housings.
My questions are:
Are these a standard fit and will my new Airmar transducers just slot into the brass housings and screw in place?
The speed unit unscrews from the through hull fitting but the depth transducer appears to be sealed in the brass housing and has a hard black coating where the wires come out. Can this be removed safely or will I have to replace the whole units including the through hull fitting?
Hope that makes some sort of sense.
Cheers,
Neil

 

[Deadline]

Caveat

You may have to solder the wire leads from the new instruments to the house wires. Check it out.

 

[Rick D]

You will likely have to replace the entire assemblies. That is what I did when I replaced my ST50 to ST60+ instruments. I tried using the old transducers but they failed within a year so I did replace them. You already know not to try to cut the new cables and splice them. Just cut the old ones to make it easier to pull through the new ones by taping them together and using the old one as a leader. Good luck!

 

[Alan]

When I replaced the ST50 speed log on my boat (it is an Airmar) I relocated it to the centerline of the boat about 18" forward of the keel so the speed reading would be identical on both tacks. Any speed log located off center will show inaccurate readings on both tacks. I also wanted a log that I could easily remove and install to prevent growth on the log. I installed a self sealing log that prevents the vast majority of water from entering the boat while I remove or install it replacing the plug. I installed a 6" deck plate in the floor of the main cabin to give easy access to the log.

PS, I did cut the wires and solder the new sensor wires to the old, it worked perfectly well.

 

[Barnacle Bill]

If you contact Ray Marine or Airamar, and tell them what you have (ST 40 or ST60 - not ST 30), then they can tell you the compatibility or incompatibility of what you have and what you want and what to get to do the job right.

 

[neilmcc]

Thanks for all of the replies.
I will take some pictures at the weekend and come back if I am struggling.