Mathmatiacly challenged member seeks assistance with speed boat science
Did someone with huge algorithm skills sit down and figure out exactly how fast and far this combination of boat and motors would perform ,prior to writing a very large check ? Or
Is there a vague shoulda ,woulda, coulda Guestimation process?
2 motors goes 12% faster than one, albeit 9% less as far ?
Three motors goes 18% faster than one motor, but ! Has to have a different prop pitch .
Four motors goes 26 % faster than one motor but has to be trimmed separately. And so on and so forth.
What's the process ? ( So that a simpleton can understand it please)This message has been edited. Last edited by: bendable,
Safety, Situational Awareness and proficiency.
Neck Ties, Hats and ammo brass, Never ,ever touch'em w/o asking first
March 10, 2026, 10:57 PM
Stlhead
There are only two items on tonight’s desert menu. Cake and Cock. And I am sorry to say that we have ran out of cake.
March 10, 2026, 11:22 PM
car541
Speed to power curves on waterborne vessels are roughly cubic.
twice as fast require 8x the power
***************************** "I don't own the night, I only operate a small franchise" - Author unknown
March 10, 2026, 11:53 PM
sigmonkey
"the meaning of life, is to give life meaning" ✡ Ani Yehudi אני יהודי Le'olam lo shuv לעולם לא עוד
March 11, 2026, 12:31 AM
bendable
The question is. Did this guy in the video start out wit a very specific goal, and sit down with a slide rule to calculate what it would take to achieve his goal ?
Or
Do people with crap tons of funds just start throwing money at boat salesman ?
I would find it hard to believe that he only required three motors, but purchased three additional motors, just in case.
There are too many variables for me to comprehend.
Safety, Situational Awareness and proficiency.
Neck Ties, Hats and ammo brass, Never ,ever touch'em w/o asking first
March 11, 2026, 01:54 AM
arfmel
It appears they purchased as many outboards as would fit on the transom of the boat
March 11, 2026, 03:01 AM
KMitch200
quote:
Do people with crap tons of funds just start throwing money at boat salesman?
Yes. People with FU money just want to flaunt/spend it. Doesn’t matter if they are spending the money wisely.
-------- After the game, the King and the pawn go into the same box.
March 11, 2026, 05:03 AM
Georgeair
You had me at "challenged".
If it makes you feel better, the half-mill estimate in video is just for the engines. the boat is another $2MM+
You only have integrity once. - imprezaguy02
March 11, 2026, 05:04 AM
4MUL8R
This is not something that is easily calculated.
Each blade is similar to an airplane wing. It creates a pressure differential as it spins, with higher pressure on its aft surface.
For each propeller configuration, of which there are three, there is a maximum thrust.
With more engine power a higher pitch prop can be selected. This can increase the boat speed.
But then the hull dynamics comes into play.
An AI investigation shows this equation…
Speed = a constant factor based on hull design and propeller capability multiplied by the cube root of power divided by the boat weight.
------- Trying to simplify my life...
March 11, 2026, 06:54 AM
chellim1
quote:
Originally posted by KMitch200:
quote:
Do people with crap tons of funds just start throwing money at boat salesman?
Yes. People with FU money just want to flaunt/spend it. Doesn’t matter if they are spending the money wisely.
+1 Sometimes, it's entertaining to watch. Usually, it's just annoying.
"Some things are apparent. Where government moves in, community retreats, civil society disintegrates and our ability to control our own destiny atrophies. The result is: families under siege; war in the streets; unapologetic expropriation of property; the precipitous decline of the rule of law; the rapid rise of corruption; the loss of civility and the triumph of deceit. The result is a debased, debauched culture which finds moral depravity entertaining and virtue contemptible." -- Justice Janice Rogers Brown
"The United States government is the largest criminal enterprise on earth." -rduckwor
March 11, 2026, 07:04 AM
joel9507
quote:
Originally posted by arfmel: It appears they purchased as many outboards as would fit on the transom of the boat
That'd be my guess also. I doubt budgetary considerations entered into the decision.
March 11, 2026, 07:43 AM
SPWAMike0317
IMHO the algorithm is: Pride + Ego = Number of Engines.
I have watched more than a few videos of boats transiting Haulover Inlet. The boats with many engines are an impressive sight. Number of engines do not seem to have any correlation to driving skill. Take a look at Blue Top Legend then watch the big multi-engine boats. More skill in that 13 foot, one engine Boston Whaler than most big boats.
Let me help you out. Which way did you come in?
March 11, 2026, 09:41 AM
Cassandra
Aren't boats HP limited by Coast Guard Regulations? Isn't there a plate fitted on every boat stating max KP, max passengers and minimum life jackets each boat is allowed / required.
____________________________ "Fear is a Reaction - Courage is a Decision.” - Winston Spencer Churchill NRA Life Member - Adorable Deplorable Garbage
March 11, 2026, 09:53 AM
chellim1
quote:
Take a look at Blue Top Legend then watch the big multi-engine boats. More skill in that 13 foot, one engine Boston Whaler than most big boats.
And those girls look like they are having fun!
"Some things are apparent. Where government moves in, community retreats, civil society disintegrates and our ability to control our own destiny atrophies. The result is: families under siege; war in the streets; unapologetic expropriation of property; the precipitous decline of the rule of law; the rapid rise of corruption; the loss of civility and the triumph of deceit. The result is a debased, debauched culture which finds moral depravity entertaining and virtue contemptible." -- Justice Janice Rogers Brown
"The United States government is the largest criminal enterprise on earth." -rduckwor
March 11, 2026, 10:00 AM
trapper189
Love those Blue Top Legend gals!
My understanding is due to the EPA and whatever other environmental government agencies regulations development of compliant diesels is cost prohibitive which leads to the plethora of outboards on the back of large boats these days. Nobody really want to fish over a transom full of outboards.
My neighbor once said owning a motor boat is like standing in a cold shower tearing up $50 bills. Owning a sailboat is like standing in a cold shower tearing up $100 bills. That’s all the math I need.
March 11, 2026, 10:28 AM
pbslinger
A buddy had a Nor Tech with triple 300 Mercurys. I think part of the overkill nature isn't just top speed, but acceleration when navigating rough seas.
Before that he had a 48 Fountain with triple 440 Yanmar turbo diesels and Arneson surface drives. It'd go about 60-65 MPH, and at a 50MPH cruise it'd get 1MPG. That's impressive for a large fast yacht. 500 gallon tanks equals 500 mile range.
Leave South Beach with a load of models at 2 AM and be in the Bahamas by morning. Money can't buy love, but it'll buy a boat that'll pull right up beside it.
March 11, 2026, 10:39 AM
trapper189
^^^100% true. A pair of 400hp outboards don’t have anywhere near the torque of a pair of 370hp diesels. The good news is there’s a lot of quality used boats out there that don’t cost a million dollars.This message has been edited. Last edited by: trapper189,
March 11, 2026, 01:52 PM
BOATTRASH1
All those Mercs are great until a couple drop a lower unit and then have to get fixed. Then another couple do the same thing and have to get fixed.
March 11, 2026, 02:32 PM
CPD SIG
quote:
Originally posted by chellim1:
quote:
Originally posted by KMitch200:
quote:
Do people with crap tons of funds just start throwing money at boat salesman?
Yes. People with FU money just want to flaunt/spend it. Doesn’t matter if they are spending the money wisely.
+1 Sometimes, it's entertaining to watch. Usually, it's just annoying.
One of the side-jobs I did was working on a boat for TowBoat US. One of our favorite sayings was: Too many dollars and not enough sense.
But that’s how TowBoat makes their money.
______________________________________________________________________ "When its time to shoot, shoot. Dont talk!"
“What the government is good at is collecting taxes, taking away your freedoms and killing people. It’s not good at much else.” —Author Tom Clancy
