Fastest boat with 3.5hp?
#21
Senior Member
Thread Starter
Join Date: Oct 2012
Posts: 1,170

The solo skiff. It was designed from the ground up by Tom Mitslaff to plane on 3.5 hp. I was involved in getting the new polyethelene models made. Tom will no longer make them out of Glass. When on plane it rides on the back third of the hull. You can see the sunlight shining under the front two/thirds. It gets 16mph and will plane through 6 to 8 inches of water. Fuel milage is insane.
All other things being equal, how does the top end of the Porta-Bote compare with the Solo Skiff given 3.5 hp?
#23
Admirals Club 

Join Date: Apr 2006
Location: NE Florida
Posts: 2,016

https://www.soloskiff.com/faq/
The speed is about 12-13mph with a 3.5Hp, and speed with a 5Hp approximately 16-17 mph. Speeds all depend on passenger weight.
HOW FAST WILL THE SOLO SKIFF GO WITH AN OUTBOARD ?
The Solo Skiff will plane with a 160 pound passenger and a 2.5 Hp Motor. The approximate speed will vary but around 8-9 mph.The speed is about 12-13mph with a 3.5Hp, and speed with a 5Hp approximately 16-17 mph. Speeds all depend on passenger weight.
#24
Senior Member
Join Date: May 2006
Location: Fort Pierce,FL
Posts: 4,507

I have no knowledge of the porta boat. I know about solo skiffs as I bought a glass one 8 years ago and then convinced Tom to get copies made in Poly by a fried of mine in Atlanta . I then became a solo dealer. I clocked mine with a gps and a 3.5 Nissan/Tohatsu. But I had way to many carb issues and now run a 4hp Suzuki.
#25
Senior Member
Thread Starter
Join Date: Oct 2012
Posts: 1,170

I have no knowledge of the porta boat. I know about solo skiffs as I bought a glass one 8 years ago and then convinced Tom to get copies made in Poly by a fried of mine in Atlanta . I then became a solo dealer. I clocked mine with a gps and a 3.5 Nissan/Tohatsu. But I had way to many carb issues and now run a 4hp Suzuki.
#26
Senior Member
Join Date: Mar 2017
Posts: 128

I've got a 4hp merc tiller that I've put on the back of a few little boats. I've had it on a variety of small aluminum boats and fiberglass dinghies and the fastest was by far an 8ft flat bottom jon boat. Sit on the deck rather than the seat and get as far forward as you can. Also have a 9 ft inflatable that struggles to get on plane as the floor isn't rigid enough as mentioned above. Inflatable is def the best bet for stability though.
#27
Senior Member
Join Date: Feb 2017
Posts: 1,338

https://www.soloskiff.com/faq/
The speed is about 12-13mph with a 3.5Hp, and speed with a 5Hp approximately 16-17 mph. Speeds all depend on passenger weight.
HOW FAST WILL THE SOLO SKIFF GO WITH AN OUTBOARD ?
The Solo Skiff will plane with a 160 pound passenger and a 2.5 Hp Motor. The approximate speed will vary but around 8-9 mph.The speed is about 12-13mph with a 3.5Hp, and speed with a 5Hp approximately 16-17 mph. Speeds all depend on passenger weight.
#33
Member
Join Date: Jul 2015
Location: Sydney, Oz
Posts: 36

According to a Porta-Boat brochure I have, the 12ft version with a 3.5 hp will plane and do 6 to 8 knots with 1 person (doesn’t stipulate weight). I don’t know if the 8 or 10 ft versions would be any quicker, although I seem to recall that the 12 ft version is the most efficient.
My 12ft Porta-Boat will do 13.5 knots with a 6hp 2st Yammy. It's a hoot!
My 12ft Porta-Boat will do 13.5 knots with a 6hp 2st Yammy. It's a hoot!
Last edited by Borrert; 01-10-2019 at 11:28 PM. Reason: fixed conversion
#34
Senior Member
Join Date: Aug 2012
Posts: 6,697

Unfortunately, no. Inflatables in that range generally won't plane with a 3.5. The bottom has a little too much give.
Even going to a 3.5hp 2 stroke, with a replacement lower pitch prop, overinflating the tubes, and using some pvc pipe to hold the tiller so you can fit in the very bow, wind and small waves going in a favorable direction, you still only have a 50/50 shot at getting it to plane.
Even going to a 3.5hp 2 stroke, with a replacement lower pitch prop, overinflating the tubes, and using some pvc pipe to hold the tiller so you can fit in the very bow, wind and small waves going in a favorable direction, you still only have a 50/50 shot at getting it to plane.
#35
Senior Member
Join Date: Feb 2013
Location: Michigan
Posts: 313

Yeah , Baby!! I built a "MiniMax" hydroplane from Popular Mechanics plans back in jr-high wood shop. That was fun. It would fly even with a 3hp Evinrude. Wish I still had it. There were 4 glassed-in water-tight flotation compartments.
https://www.youtube.com/watch?v=gqTcuUMCwh0 ( 4 hr build in 8 minutes)
https://www.google.com/search?q=mini...990oCjVgqWMDM:
Mine was red with white stripe.
Highly recommended easy project guaranteed to put a grin on your face.
https://www.youtube.com/watch?v=gqTcuUMCwh0 ( 4 hr build in 8 minutes)
https://www.google.com/search?q=mini...990oCjVgqWMDM:
Mine was red with white stripe.
Highly recommended easy project guaranteed to put a grin on your face.
i think I am going to buy stock in drywall screws.
#36
Senior Member

Join Date: Oct 2003
Posts: 7,322

Unfortunately, no. Inflatables in that range generally won't plane with a 3.5. The bottom has a little too much give.
Even going to a 3.5hp 2 stroke, with a replacement lower pitch prop, overinflating the tubes, and using some pvc pipe to hold the tiller so you can fit in the very bow, wind and small waves going in a favorable direction, you still only have a 50/50 shot at getting it to plane.
Even going to a 3.5hp 2 stroke, with a replacement lower pitch prop, overinflating the tubes, and using some pvc pipe to hold the tiller so you can fit in the very bow, wind and small waves going in a favorable direction, you still only have a 50/50 shot at getting it to plane.

#37
Senior Member
Join Date: Aug 2012
Posts: 6,697

I could get the Johnson 3.5 2-stroke to plane my 8.5 foot inflatable consistently IF I pushed down on the bottom with my foot just at the right spot to make it rigid enough to climb over the bow wave. Been a while but as I recall the sweet spot was typically just in front of the thwart seat. One of the great measures taken to eek more speed out of the inflatable. 

#39
Admirals Club




Join Date: Jul 2005
Location: Miami Fl / Washington NC
Posts: 1,908

Keep threads like this coming.
My 67 year old Mercury mark 5 planes my daughter and I (260 lbs. live weight) in her Mini Max at 24 mph.
Check out 2:50 in the video. Sea gull racing. That's an oxymoron if I ever heard one.

My 67 year old Mercury mark 5 planes my daughter and I (260 lbs. live weight) in her Mini Max at 24 mph.
Check out 2:50 in the video. Sea gull racing. That's an oxymoron if I ever heard one.


#40
Senior Member
Join Date: May 2006
Location: Fort Pierce,FL
Posts: 4,507

It was a new 4 stroke and whereI live on an island Im sure I had the wind and tide to my advantage, Do not even consider the Tohatsu/mercury/nissan they suck. Get a Suzuki.