What are these then?

[rbcoomer]

Anyone know what these are? They were sited either side of the sterndrive near the base - approx 8" away (i.e. below waterline) One connects via a single brown wire and one via a single orange wire. The engine is a Volvo 5.0 V8 (Carb - I think probably an AQ200D?) and drive is an Alpha 1 Gen 1 - although I guess would have been a Volvo unit originally. As I'm replacing transom, I wondered if they actually served any useful purpose and needed refitting/replacing. The hull is now bare so I shouldn't have a problem tracing the wiring if nobody can shed any light...

 

[sarabande]

1970's version of ultrasonic antifouling ? One deals with rectilinear barnacles, 'tother with pointy ones.























NO, no idea, except that in some standards red and black were pos and neg.

 

[rbcoomer]

Hee hee! A friend kindly suggested that as the engine was Volvo, they were probably 'parking sensors'...

I'll add ultrasonic a/f to my list of possibles then.

 

[rbcoomer]

A couple more pictures in-situ, if it helps:

 

[superheat6k]

They're so you can talk to your water skier - just before you turn him into mince meat !

 

[rbcoomer]

Crikey - presumably they need to be ultrasonic then and he/she a Dolphin?

Interestingly I was working on some kind of send/receive like ultrasound, but there are no displays etc in the boat - so unless removed that rules out any kind of echo unit. Also, why facing backwards not down?

Also pondered anodes of some kind, but not enough metal/no means to replace...

I would pull them apart and have a look inside, but if I need them and can't get any more it doesn't seem a good plan

 

[rosssavage]

Impressed current cathodic protection?

 

[[2068]]

Looks like a dodgy old electrical "anode protection system".
Best stored in the bin.

 

[rbcoomer]

Impressed current cathodic protection?

Possible, but seems overkill for 21' GRP sportsboat, no sign of shorepower connection of any kind and nothing other than bilge bypassed the isolation switch to battery so if it was, then long since disconnected!

I thought that type of system was used on large steel/iron vessels, but will do some reading up!

 

[rbcoomer]

Looks like a dodgy old electrical "anode protection system".
Best stored in the bin.

That's where they were heading - until that 'what if' moment reared it's head...

 

[AndieMac]

Impressed current cathodic protection?

The two external sections are part of a "Mercathode" galvanic corrosion system, the rest of it looks like a "buzz bar" attached inside the transom near the battery system.

 

[Racingfrank7]

I am still liking the previous post of parking sensors !!!

 

[rbcoomer]

Thanks Andie - I'll do some research and Google for that and see if it's worth refitting. The boat will be trailered so the anodes will probably suffice. I didn't see any internal bits fitting that description but will go through the stockpile in the garage and the 'dis-assembly' photo library...

 

[AndieMac]

It's a pretty old school system Robin, most Merc. powered trailer boats in this country have had them fitted, from memory since the very late seventies. My current boat has them, but I reckon the concept is definitely aimed at corrosion on the moored boat.