What is the black plastic/rubber screw on ball ?

[ImaFirstMate]

What is this black ball on the starboard stern of this boat? It unscrews and comes off. It's just a screw underneath.

 

[Indysailor]

Oh my God! Don't unscrew it!

 

[Richard19068]

Looks like a mount for some kind of display device.

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Although that looks like an odd position for that so probably something else. Maybe a bimini support mount?

 

[dlochner]

Looks like a base for a small crane to lift outboard motors off a dinghy. Look for evidence of a mount for an OB, and look for clamp on the rail to stabilize the crane. Here's one example of an OB crane.

Boat Nova Lift

Forespar's Nova products combine elegant styling with superb strength and function. The Patented Nova Lifts lets you keep the lifting arm centered over the load. Other brands swing left and right without control. Another valuable feature is the internal lead to your cockpit winch where you have...

www.forespar.com

 

[Captain Larry-DH]

Looks like a base for a small crane to lift outboard motors off a dinghy. Look for evidence of a mount for an OB, and look for clamp on the rail to stabilize the crane. Here's one example of an OB crane.

Boat Nova Lift

Forespar's Nova products combine elegant styling with superb strength and function. The Patented Nova Lifts lets you keep the lifting arm centered over the load. Other brands swing left and right without control. Another valuable feature is the internal lead to your cockpit winch where you have...

www.forespar.com

This. Forespar Motor Mate base. A small crane for hoisting an outboard motor.

 

[Steve_Catalina]

How about a pole mount for radar? with the waterproof hole for the cable between his fingers.

 

[dlochner]

How about a pole mount for radar? with the waterproof hole for the cable between his fingers.

Unlikely, the radar cables are really fat, that hole isn't.

 

[Joe]

Da Ding .......... the Whatzzitt prize goes to Capt Larry

 

[Stu Jackson]

Da Ding .......... the Whatzzitt prize goes to Capt Larry

AND to Dave. Forespar and Garhauer. The Garhauer balls aren't shiny. Sorry, I couldn't resist.

 

[Captain Larry-DH]

AND to Dave. Forespar and Garhauer. The Garhauer balls aren't shiny. Sorry, I couldn't resist.

The Forespar balls also get quite dull. If you want shiny balls you need to clean and polish them.

 

[GeorgeC]

The ball is the base for a Forespar Motor Mate Hoist used to lift your outboard on and off your dingy. There should be a SS ring mounted above it on the stern rail. The lower vertical white aluminum pipe of the hoist runs through the SS ring and rests on the ball mounted on the boat and the hoist arm assembly fits into the upper section of the vertical pipe. Motor Mate

 

[R Squared]

Forespar did not produce the ball base fitting pictured. Also, the Motor Mate has not been in production for several years now, even though some Lift attachment parts might still be available. The Nova Lift is currently available.