Inboard vs. I/O

[aggiedave98]

I'm not sure if this is the right forum but right now I've got a '89 Invader 17.5' I/o with the 3L 4 cyl mercruiser.

I'm thinking about a new boat.

It's really hard to find info about the pros and cons of inboard vs. I/O. Can you guys help? I like water skiing and wakeboarding, but I'm not great at either so I don't have to have a really great skiing boat. I've got a young kid (2 yrs) and will probably have more, so I kind of want something that's good for the whole family and something I can keep for 15 years.

Any advice??

 

[ezmobee]

Re: Inboard vs. I/O

I misread the question so I'm removing my useless comment

 

[aggiedave98]

Re: Inboard vs. I/O

One other thing... I'm looking for a 19-21 foot boat probably...

 

[salty87]

Re: Inboard vs. I/O

i was going to tell you to try a search, glad i tried it first because i couldn't find anything.

some pros for an inboard:
- maint and repairs are about as easy as they get. no outdrive
- safety, prop is under the hull
- they hold their value pretty well

cons:
- not very efficient since you can't trim the drive (bigger engines, drinking more fuel)
- prop can't be tilted up so they have a deeper draft and if you hit something, you'll need something repaired. i/o is a little more versatile in shallow waters.
- they usually have low freeboard so i'd stick to inland lakes

 

[aggiedave98]

Re: Inboard vs. I/O

i was going to tell you to try a search, glad i tried it first because i couldn't find anything.

some pros for an inboard:
- maint and repairs are about as easy as they get. no outdrive
- safety, prop is under the hull
- they hold their value pretty well

cons:
- not very efficient since you can't trim the drive (bigger engines, drinking more fuel)
- prop can't be tilted up so they have a deeper draft and if you hit something, you'll need something repaired. i/o is a little more versatile in shallow waters.
- they usually have low freeboard so i'd stick to inland lakes

thanks. Yeah, I tried both google search and searches here and VERY hard to find info. What is a low freeboard??

Can you elaborate on trimming and the implications?

 

[salty87]

Re: Inboard vs. I/O

thanks. Yeah, I tried both google search and searches here and VERY hard to find info. What is a low freeboard??

Can you elaborate on trimming and the implications?

freeboard- the portion of the side of a hull that is above the water. inboards sit kinda low in the water. i/'o's tend to sit a little higher. in open water esp if it's rough, you want to have a higher freeboard. if you have both boats on the water, the gunnel of the i/o will be higher than the inboard...usually.

trimming an i/o allows you to pick the optimal angle for the outdrive given the speed and conditions. with an inboard, you can't change the angle so it may not be most efficient for that speed. you won't find any 4 cyl or 6 cyl inboards in ski boats.

 

[tommays]

Re: Inboard vs. I/O

On and Inboard in that size range Pretty much everything is going to be a SKI BOAT

Good boats BUT when there geared for sking the hull tends to not be the best rideing for non-skiing use


Tommays

 

[dingbat]

Re: Inboard vs. I/O

not very efficient since you can't trim the drive (bigger engines, drinking more fuel)

Inboards are very efficient when run at their design speed. They are not speed demons, with the exception of some of the ski boats with hulls designed for the purpose, but when run at their design speed they are extremely efficient. Combine a keel or pocket drive with a diesel motor and you’re looking at 3-5 gallons per hour fuel consumption at cruising speed.

Larger boats than your looking for but it contains some more information about inboards
http://www.shamrockboats.com/content.php?p=shamrock_advantages/keel_drive_advantage.html

 

[DaveM]

Re: Inboard vs. I/O

Something to keep in mind is that there is not a single boat design that can do everything, so this means trade-offs. Nothing, and I mean nothing, beats the tiny wake of an inboard for water skiing on flat water. But add a little chop and that ride will beat the snot out of you. Bottom line, go with the inboard if your main purpose is to ski and you will not be disappointed.

 

[QC]

Re: Inboard vs. I/O

add a little chop and that ride will beat the snot out of you.

This is true even of the newer V-drive inboards with a deeper V for Wakeboarding. Also, the efficiency comments are always true. Inboards are less efficient than I/Os of the same size. I/Os are mechanical nightmares and that's why they require a healthy dose of consistent maintenance. If maintained properly no biggee.

To elaborate more on the trim deal . . . Inboards are fixed angle drives and they push slightly downward as there is no other way to run a straight shaft from the engine to under the boat without punching through at an angle. This makes them outstanding for getting out of the hole and pulling skiers. Wakeboarders on the other hand do not require near as much power to get up, so non-issue with an I/O if you ask me. With an I/O it can be trimmed for decent hole shot and then trimmed up or out, for higher speeds and much better cruise efficiency. If you operate in shallow waters, or like to beach your boat, the I/O or an OB is the only real choice. There is no way to "save" an inboard if you make a mistake and stray into shallow water. With an I/O or an OB you can react to shallower water than expected.

Despite my notes above I love inboards for their simplicity and solid feel. But if you plan to cruise more than you plan to run comp style skiing and Wakeboarding, in my opinion the I/O is the only choice unless you are considering OB power. I/Os are much better for relaxing and swimming than OBs though. Good luck.

 

[Buttanic]

Re: Inboard vs. I/O

I have found that my 22 foot center console inboard I have now handles a chop much better than the 24 foot center console I/O I had did. With the center of gravity lower and more forward than the I/O it doesn't bounce the bow and slap the water like I/O did with all the weight at the stern. Trim tabs are a must have on any inboard.

 

[QC]

Re: Inboard vs. I/O

I was comparing runabouts and ski boats . . . I am sure there are many exceptions, but most if not all inboard and v-drive bowriders etc. have shallower degrees of deadrise than most I/O runabouts. With that said . . . there are 16 degree "deckboats" that will slam more than a deeper v-drive . . . Yeah, my comment was too general.

 

[aggiedave98]

Re: Inboard vs. I/O

thanks guys. VERY big help. I think I'm going to go with an I/O. Probably makes more sense for what I need it for. Now the question is new or used...

 

[ezmobee]

Re: Inboard vs. I/O

My vote would be used. Boats depreciate pretty fast so you can get very nice newer boats for 1/3 to 1/2 off. That's a lot of savings even if you have a few bugs to work out. But I'm the same way with cars. I let someone else pay the depreciation. I'm sure the financing options are way better on new boats though.

 

[RC]

Re: Inboard vs. I/O

Aggiedave, if you want more info on the benefits of an inboard boat for wakeboarding/skiing post your same question on this site: http://www.wakeworld.com
They also have a great section of used boats for sale that you can take a look at and compare.

I've got an older I/O and am quite happy with it. Great family boat for cruising or just hanging out and swimming and also throws a decent wake for wakeboarding.

Good luck!

 

[chaparral442]

Re: Inboard vs. I/O

don't be afraid of used but do check them out - I looked at two boats both under 50 hours --test drove the first one and it ran hot--owner had stored, impeller got brittle- he knew nothing about boats --I ran from that one even though it looked great

Boat I bought was like new - young owner bought it at a boat show and could not handle the notes. I picked it up for less than what he owed and at wholesale price

Not sure how your state works but in Louisiana you only pay sales tax on a boat when it is new. If you buy it used there is no sales tax-- that alone could be a significant savings

 

[aggiedave98]

Re: Inboard vs. I/O

don't be afraid of used but do check them out - I looked at two boats both under 50 hours --test drove the first one and it ran hot--owner had stored, impeller got brittle- he knew nothing about boats --I ran from that one even though it looked great

Boat I bought was like new - young owner bought it at a boat show and could not handle the notes. I picked it up for less than what he owed and at wholesale price

Not sure how your state works but in Louisiana you only pay sales tax on a boat when it is new. If you buy it used there is no sales tax-- that alone could be a significant savings

wow, that's great. I'm pretty sure Texas makes you pay tax no matter what.

 

[chaparral442]

Re: Inboard vs. I/O

I would check it out- you pay tax on the trailer because it is titled. Unless Texas titles the boat- all you do is change the registration with the State Wildlife department

 

[aggiedave98]

Re: Inboard vs. I/O

I would check it out- you pay tax on the trailer because it is titled. Unless Texas titles the boat- all you do is change the registration with the State Wildlife department

hmmm... this looks like you do have to pay it in texas...

http://www.window.state.tx.us/taxinfo/boat/boatfaq.html

 

[magster65]

Re: Inboard vs. I/O

Howdy. I'd opt for the I/O myself, aspecially if it's not sitting in the ocean.
* They can be trimmed up to run faster or in shallow areas for clearance
* Trimmed down to help a boatload on plane
* Easier to change or service props
* Props are 'everywhere' for them
I like the shaft drives because of the (almost) zero maintenance but I think they suit a bigger ocean boat than a lake boat. I hang out with a bunch of hot rodders... I've seen a lot of dough spent on this stuff! Merc should use this in their ads; One 'yahoo' I know has had at least 10 600 hp plus engines in his boat over the past 7 or 8 years, he's blown them all up by jumping waves or running at way too high of rpm for extended periods... he beats on the thing like a madman! The stock bravo drive (with a shower on it) is still in perfect shape, oil comes out clean and it shifts nice. There's a lot to be said for that kind of durability.