What Size Outboard for Emergencies

rcolman

Cadet
Joined
Feb 22, 2009
Messages
8
I need an emergency second outboard for my 18' runabout. I am trailering it to the Sea of Cortez, and if my main engine goes out, I need to get back to shore. No Coast Guard, Vessel Assist, etc. available.

The boat weighs about 2000 lbs. I need the smallest and lightest possible motor size to get me back to shore at, say, 4 or 5 miles per hour. May encounter 10-15 mph winds or moderate currents on the way back in.

What is the smallest HP recommended for this purpose? Hopefully, the motor will stay under the bow and never get used, but, you never know.

Rick Colman
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: What Size Outboard for Emergencies

i would say minimum, 9.9 make sure the shaft is long enough to get deep enough, and not get swamped by a following sea.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: What Size Outboard for Emergencies

On my old, closed bow, 18 foot runabout, an 8 Hp only pushed it at 3 MPH in calm water. And, as the boat rolled from other wakes, the prop almost broke the surface of the water. I would say you would need a 15. Either that or a 10-15 sailor model. Sailor models have a large diameter high thrust prop to move a displacement hull efficiently, (which your runabout would be at those speeds) and the prop is buried deeper to account for rolling of the hull.

Sailor model is a better choice if you can find one used or can afford the extra cost.

I put my money where my mouth is: I just bought a used sailor model 10 HP engine for emergency use on my 21 foot cuddy. AND, I may swap out the powerhead with a 12.9 or 15 that I have laying about if the 10 proves to be too small.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,385
Re: What Size Outboard for Emergencies

I'm on the 9.9 bandwagon as well. Great advice already given about shaft length and thrust.
 
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