What Size Kicker Motor

[DaboatnutinWA]

I have a 1988 21ft Sea Ray express cruiser. Weighs about 3800ish with everything including me and the wifey. Need to know how big of a kicker motor I should get for emergencies if the main engine dies for some reason. Im mostly in the brine and have to deal with tidal currents so What H.P should I get?

 

[smokeonthewater]

A good anchor and seatow would be my suggestion.

Otherwise 15-20 hp

 

[cptrick3]

I have a friend with a similar size boat with a 9.9 2stroke. Seems to work for him. On the Columbia river he may have a 3 knot current to deal with.

 

[DaboatnutinWA]

Thanks for the reply. Yes, I have a good anchor and ground tackle also probably going to get signed up with Vessel Assist as well. I figure can't be too safe.

 

[airshot]

I have a 22' aluminum hull, about 2500 lbs with a 9.9 kicker and it can go 10/12 mph in an emergency so my recommendation would be 15-20 should do you well.
I like the comfort of knowing I can get back to shore if the main motor should fail.

 

[JoLin]

Yup. If you're gonna do it, 15-20 should work fine.

 

[ondarvr]

Most people in our part of the world (Puget Sound) use a 9.9 high thrust motor for that application. You can go with a larger one, but the cost, weight and hassle go up without a great deal of benefit.

 

[DaboatnutinWA]

Most people in our part of the world (Puget Sound) use a 9.9 high thrust motor for that application. You can go with a larger one, but the cost, weight and hassle go up without a great deal of benefit.

Thanks Ondarvr for the insight on the cost vs weight issue. Yes I see alot of those 9.9 Mercs. I was leaning towards that size since they are so plentiful and I think now its perfect for my application and intended use.

 

[UncleWillie]

A 21 ft boat will have a "Hull Speed" of about 7mph. You might be able to push it up to 8 or 9 with a lot of extra power.
To double the speed under ideal conditions, requires 8 times the Power.
So, unless you can generate enough power to get it on plane, the difference between a 9.9 and a 20 will be very minor.

 

[bobdec]

+1 Yep I agree..top displacement speed for a 21 is about 7 MPH, I'd go with something like a "High thrust" 9.9 Yamaha . Less prop pitch more torque helps keep the RPM up there so you don't overload it when pushing that much of a load. When shopping keep in mind a 21 footer has different operational requirements than something pushing a skiff around. I'd also add that I would only classify a kicker on a 21 ft cruiser as a "fair weather" emergency backup. Not sure if will be capable of maintaining control that boat effectively in snotty weather.