Actual mph(speed) comparisons.Post your highest speed.

[QC]

Re: Actual mph(speed) comparisons.Post your highest speed.

23 ft Carrera, 6.2 Mercruiser 320 Bravo 1, 57 MPH GPS
14 ft Sea Nymph, 5 bhp Briggs and Stratton, 11.9 MPH GPS

 

[chaparral442]

Re: Actual mph(speed) comparisons.Post your highest speed.

2006 190ssi Chaparral 190hp@4600rpm--51mph with 4 adults and full tank of gas-- bend the prop a little more, add exhaust tube, syn oil and my goal is 55mph

 

[Solittle]

Re: Actual mph(speed) comparisons.Post your highest speed.

196? 12' tinny - 2 oars - no GPS or speedo - could walk faster - maybe I'll take a nap.

 

[anthony115merc]

Re: Actual mph(speed) comparisons.Post your highest speed.

18 ft bondwood boat 25hp merc people walk faster than it on the shore slapping a 115 inline 6 merc on soon

 

[Bondo]

Re: Actual mph(speed) comparisons.Post your highest speed.

hey bond-o ..... that is really interesting .... why would your boat be 11mph faster in saltwater? .......

Ayuh,........

The 1st time I did it,... It baffled Me for alittle while,.....Maybe 8 or 10 miles,.....
Then it dawned on Me,........ It's Simple Physics........

Saltwater is MUCH Denser than Freshwater,......
So much so, that a Steel Tank, full of Freshwater, will Float in Saltwater.........

So,........
The Prop Bites Harder, with Less Slip,......
And,.....
The Hull rides Higher in the water, because of the Density........

So the Prop,+ Hull are Much More Effiecent in Saltwater..............
Hence the Higher Top Speed...............

 

[anthony115merc]

Re: Actual mph(speed) comparisons.Post your highest speed.

mine doesnt go 11mph faster in salt water it tends to get pushed bakwards by waves

 

[Pony]

Re: Actual mph(speed) comparisons.Post your highest speed.

My numbers arent nearly as impressive as the rest of yours......

14ft Alumacraft
25hp Johnson from my avatar
GPS speed 32mph.........though usually I am more or less around 28-30mph. Just one time I had some really good balance and perfect conditions

 

[QC]

Re: Actual mph(speed) comparisons.Post your highest speed.

Methinks Bondo makes some sense, but me also thinks he was going into a current in fresh and with a current in salt . . . :duckingincasebondothrowssumpin':

 

[Bondo]

Re: Actual mph(speed) comparisons.Post your highest speed.

I Donno QC,......As you've figured out,.....
I live Logic,+ That's the Only Explanation I can come up with.........

My boat will run 42/43mph,gps about Any day you want to Run it,.....
I see Slightly higher speeds when boating in Nov.,+ Dec.... When the Water is about to get Hard........
And,.....
I've hauled this Barge up to Maine 3 times now,+ Everytime I run it in the Salt, It runs 52+mph,gps......
Once in Penobscot Bay,+ Twice in Frenchman's Bay........
When I haul it out of the Salt,+ to Chemo Pond where the Family Lodge is, Just 30 miles from the Ocean.....
I resplash it in Chemo to run it,+ get Rid of the Salt residue,......
It's back to 42/43 mph,gps.......

If you've got a Better Explanation,.............. I'm All Ears...............

 

[Frank Acampora]

Re: Actual mph(speed) comparisons.Post your highest speed.

6 foot john boat--25 hp Johnson--60 seconds over a measured mile--60 MPH

 

[kenmyfam]

Re: Actual mph(speed) comparisons.Post your highest speed.

Doral 164. 140hp 1985 Johnson.
14" X 17" prop.........46 mph at 6,200 rpm
14" X 19" prop.........46 mph at 5,400 rpm
Speedo and GPS verified.

 

[Aquaman]

Re: Actual mph(speed) comparisons.Post your highest speed.

1988 Chaparral 1900SX 4.3 14.5 x 17p SS prop. 41.6 mph/gps @ 4800 rpm. 2 adults ,2 teens, 1/2 tank fuel.

 

[thurps]

Re: Actual mph(speed) comparisons.Post your highest speed.

Once rode in a Glastron/Molinari at 94 mph. Had to change my shorts.

 

[SpinnerBait_Nut]

Re: Actual mph(speed) comparisons.Post your highest speed.

My signature boat.
24P Raker, 45 gallon of gas.
Full fishing gear and myself.
Last try after break-in,
79 on GPS.

 

[Scout Sport Fish]

Re: Actual mph(speed) comparisons.Post your highest speed.

185 Scout (CC Sport Fish) 130 HP Yamaha 2 stroke. I got it up to 55 last year or think? (Or was it 45?...God its been to long I cant wait to get her back in the water again.)

 

[QC]

Re: Actual mph(speed) comparisons.Post your highest speed.

Everytime I run it in the Salt, It runs 52+mph,gps......

I resplash it in Chemo to run it,+ get Rid of the Salt residue,......
It's back to 42/43 mph,gps.......
If you've got a Better Explanation,.............. I'm All Ears...............

Nah, current is the only one I had. I don't think you'd post it if you weren't sure, but that is still weird . . .

 

[Panel guy]

Re: Actual mph(speed) comparisons.Post your highest speed.

1982 Bass Tracker tx 17 with '98 Johnson 70 hp,14 x 17 aluminum prop 37.1 mph/gps with the wind, 36.4/gps into
Trying a 14 x 19 prop tonight

 

[studlymandingo]

Re: Actual mph(speed) comparisons.Post your highest speed.

18'6" Winner center console. 150 V-6 Mariner, about 40 gallons of fuel, 3 adults and one Golden Retriever, 21p SS prop, 5200 RPMs 44mph GPS. Feel like I should be able to get a little more speed. I would like to get a little higher WOT, but not sure a 19p prop is the answer; I've had my eye on some setback plates!!​

 

[Jason Edwards]

Re: Actual mph(speed) comparisons.Post your highest speed.

2000 Center Console, 200 Johnson Oceanrunner turning a 17P Rapture. I get 48 mph on smooth water with light load at 5700 rpm.

 

[fastempo]

Re: Actual mph(speed) comparisons.Post your highest speed.

No, it is not that the salt water is "greasy". A boat will be faster in salt water, because salt water has a higher specific gravity than fresh water. Or simply, salt water is heavier than fresh. Thus, correspondingly a boat will float higher in salt water than in fresh, because the volume of water the hull displaces, times it's unit weight per cubic feet, equals the weight of the boat. (The principle of that famous and ancient Greek scientist, a guy named Archimedes, you may have heard of.) So higher weight salt water means less volume of salt water to displace, compared to volume fresh water required to displace at flotation. So finally, floating higher means higher speed in salt water, as there is less wetted surface, meaning less friction and drag in salt water