Trolling motor shaft length

Boats up to 15' for oars, power or sail. Please include the boat type in your question.
JPBoater
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Trolling motor shaft length

Post by JPBoater »

Hello, all. I'm new to the forum and haven't built a boat yet. I am getting a Walker Bay 8 as a gift, and I want to buy a Minnkota trolling motor for it. Walker Bay customer service is non-existent, so I'm left to my own devices. Here are my calcs/logic:

My calcs are:
6” of shaft above the transom
21” to the boat bottom (includes skeg - the very bottom)
4” to the top of the prop (anti-cav)
3” net to the top of the prop housing (9” prop, ~3” housing, so 4.5-1.5=3)
that's 34”, so 36” shaft

Am I right? My (typically) smarter brother says 42", but I don't want the tiller/throttle way above the transom....

TomW1
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Re: Trolling motor shaft length

Post by TomW1 »

First I assume this is transom mount and you are 5' 10" or taller. So you want the tiller about 12" higher than the transom seat. So let's start with the height above the transom of 10", Then the shaft to the bottom of the hull is 21" and we want the prop to be clear of any interference by the boat so we put it down 10" below the boat. So 10+21+10=41, so your brother was right a 42" shaft is correct.

Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

JPBoater
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Re: Trolling motor shaft length

Post by JPBoater »

Drat, foiled again! Thanks!

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