9.9 hp on a 12.6' inflatable???

[UCF]

I am thinking of purchasing an inflatable from west marine. Its 12.6' weighs something around 180 pounds. I have access to a 9.9 mercury 4 stroke. Boat is rated for 25hp, but doesnt list the transom max weight. I know it would be better if I had a 25 hp.

Question is, would the boat be able to get onto plane with 2 people (390 pounds) plus dive gear?

Looking to do some beach launches off of south florida.

Thanks,

Eric

 

[herbdb]

Probably not with two people and gear. We used a WM 10.5 dingy with a fiberglass floor on our sailboat as an auxillary. The 9.9 engine would push it along well with two people, a dog and groceries, but it would not plane. I think you should go for a larger engine. The problem is that the weight of the motor goes up rapidly and you will be manhandling the boat and motor through surf.

 

[UCF]

Thanks for your input. There were two people in west marine when I was speaking to the sales associate that both had inflatables. Both of them basically said the same thing. Back to the drawing board.

 

[DA Aquamaster]

We'vre looked at the same option for river cave diving in FL. In that application, the ability to plane is not as important as the distances are fairly short - but offshore is a different story.

 

[Mr.X]

As mentioned by DA - offshore you'd want some gidde-up.' That said 9.8 would move you and a buddy with gear along, though not spritely in mild, to moderate waters. I would imagine the max transom weight for a 12' RIB inflatable being around the 180 lb mark? Much less for non RIB. A Merc/Tohatsu 4 stroke is something like 90 lbs so you are well within limits.

 

[Wookie]

Don't limit yourself to the Merc you have available. you can pick up some real steals on smaller outboards, at least in the keys, where sailors living the dream come to have their dreams die. I've seen in the few short years I've lived here many sailors on well appointed boats come here and have to sell dingy, outboard, sails, and basically end up with a hull before they go completely broke and go home to mommy and daddy and leave their hull to sink in the next storm. I picked up a very respectable 3.1 meter Zodiac last year for $200. I've seen new (post 2005) Johnson 9.9 hp outboards for $500. A tuneup and new water pump will get you bouncing through the surf in no time. Find the place in West Palm or Dania or Stuart where dreams go to die and start your own dream of boat ownership.

 

[Maples]

We run a 3 meter inflatable, usually only for two of us plus gear. It originally had a 9.9hp but it struggled, especially when the gear was wet after a dive. We traded the smaller motor in for a 15 hp (which actually didn't weigh much more) and it's a much improved ride. Sometimes we dive 3 out of it and the 15 copes with that ok too.

 

[The Chairman]

What is the dingy intended to do here? There's a lot of difference in need from using it as a shore to mooring ferry or as a longer distance dive boat.

 

[jar546]

This may do the trick

 

[VooDooGasMan]

UCF your on the right track,
1 you have picked the 12'6'' which is bigger flotation and not much more weight than a 10', which will help balance weight of dive gear.

2 your in florida and have small weight belts, a big plus.

3 a 15 hp is a 10 hp just a different carb on most makes.

4 A dolphin hooks to the cavitation plate on your ten hp that lifts the back up to plane, with an attached to back of transom plate does this also and you can use both. This has better fuel economy also.

5 AL anchor, and unless needed gas use a small fuel tank. when going far, the fuel will be less weight on the way back.

I now use a 5 hp 2 stroke merc on a 12'6" zodiac MkII C GT, with a dolphin on motor and a 3 1/2 gal tank. the tunes are bigger than others this size. I use 22# weight belt, and I get on a plane and cruise pretty good. I get on side of toons to drain water from suit and I drain water from bc before getting and putting in boat.

I have a 25 for it also and it is if I need for another diver, but I have a big RIB zodiac for that.

The lighter the motor the more you like dealing with it.

You will learn how to make it work and it is very easy on the pocket book per dive.

My 5 hp set up is like $.35 a dive of three mile trip about.

I also use a tiller ext, and have a rope in front I hang on to when surf is up and stand up for less weight on toons.

Have fun as it is fun just to go diving as it is diving.