Which is best and why?
l will start with my favour for outboard.
you can replace as needed with minimum cost .
Onboard I see zero advantage or future for !
I could be wrong ??
I have an outboard on my boat. Well two options really. A 3.5 and a 15 hp. I am shifting 3.2 tonnes on a 22' Hull. The 3.5 gets me in and out of the marina but in any chop is useless as the boat pitched and the prop comes out of the water then cavitates as it goes deep again. It starts easily and is fairly light so comes up and down on the bracket nicely. The 15 is a beast, harder to start and heavy so lifting the thing on the bracket is a chore. It will take just about any chop and punch the boat through whatever is dished up. I went the outboard route as I would have needed a full motor/ shaft/prop/ fuel tanks etc. Just the engine would have been the cost of the boat.
If I had the money I would get an onboard engine. Easy to start, prop is down deep. It would need a folding prop. Flip side is more maintenance and more systems means more failures.
30 ft fb
Repowered with 5.7 mercruisers 7.5 yrs ago.
Did not even consider pods and outboards ( why would you mutilate a good hull with egg beaters and then find it rides, handles and floats like a dog afterwards ?? )
Very expensive mistakes been made there and ya don't have to look far to find them, specially if you live a block from the boat ramp.
Like l do.
23 ft diesel huntsman.
Outboards?
Not happening.
30 ft timber displacement hull
Inboard
17.5 cuddy cabin
Outboard
15 ft runabout.
Outboard.
They are the boats we currently have.
There's been a heap of others.
Skiboats, tinnies, halfcabins, cruisers ..." sundries too numerous too mention "
If it was designed with inboards leave it as is.
It is a mortal sin to do otherwise.
If it was designed with inboards leave it as is. Well my boat had an inboard but it was dead and I got rid of it and use an outboard. Put a water tank where the engine was for trim and water use. Oh well.
Then I found the plans from 1937. Guess what? No engine...and a water tank in the same place! I must be a design genius. I suppose in those days you sailed on and off moorings so not as much need of a motor.
I do do have an old Seagull that would push it and look the part but so far have spared people the din and 10:1 fuel mix.
In a yacht? Horses for courses anything over 30ft is gonna be to big for an outboard (realistically). If you wanna use this boat for cruising then an inboard is gonna be better becuase in a swell the prop wont be lifted out of the water and will be more reliable over time ( if well maintained).
EDIT: i realise you are probably talking about powerboats. Yeah i couldnt see myself putting a new inboard in a boat. Outboards all they way
1. Give you more space
2. Probably cheaper
3. Probably more fuel efficent
4. Easier to do maintaince on
5. Easier to find parts for
6. These days you get 5-7 years warranty on new outboards.
Have you had inboards previously?
Have you priced 2 new 300 hp out board motors lately?
How much to fit them?
Have you priced transom repairs/ adjustments and assorted costs to suit outboards?
Have you ran those size motors at WOT ( l have a mate who uses around 250 litres an hour at WOT....at around 48 kts.
I don't go that fast but don't use anywhere near that either.
I paid 25k for two new 5.7 mercruisers and another 25 k for fitting/ fibreglassing/ beds/cabin work haulout etc etc blah blah.
No one does their own servicing on new motors anymore, unless they want to void the warranty.
My donks are mostly under the cabin floor so little room is lost.
Have a dive door in the transom easy to get back in the boat without eggbeaters in the way.
No change in boat handling or ride.
Three things that a diesel inboard has over an outboard.
1. Quieter, ear muffs are really needed for an all day motor with an outboard!
2. More fuel efficient
3. Most importantly, the fuel is a lot less volatile!
Select to expand quotetired said..
Have you had inboards previously?
Have you priced 2 new 300 hp out board motors lately?
How much to fit them?
Have you priced transom repairs/ adjustments and assorted costs to suit outboards?
Have you ran those size motors at WOT ( l have a mate who uses around 250 litres an hour at WOT....at around 48 kts.
I don't go that fast but don't use anywhere near that either.
I paid 25k for two new 5.7 mercruisers and another 25 k for fitting/ fibreglassing/ beds/cabin work haulout etc etc blah blah.
No one does their own servicing on new motors anymore, unless they want to void the warranty.
My donks are mostly under the cabin floor so little room is lost.
Have a dive door in the transom easy to get back in the boat without eggbeaters in the way.
No change in boat handling or ride.
If your boat was designed with sterndrives and they are in good condition then yeah keep them. I reckon if you built a new boat and i had to decide whether i wanted a sterndrive or outboard i'd take an outboard. Old sterndrives, im my experince are nothing but problems. Although if you got them new they should be reliable
Select to expand quotetired said..
So thats a no to all the questions l asked.
Got it.
Correct
Depends on your outboard. If the water intake is under the cavitation plate, it's relatively simple to adapt or make a clamp on plate with hose fitting that goes over the water inlet. A half bucket of fresh water will get you a decent flush.
