small boat - inboard vs I/O vs outboard

[skyhawk]

sitting in traffic today on a trailer I saw a nice looking center console.... very roughly 25ft length range...full inboard drive
It was a beautiful looking boat...nice lines. I couldn't see the make or model

What would you say the advantages for a full inboard drive on a boat in this size range?...A planning hull go fast boat...

This one was much more seaworthy looking than the ski natiques...but same idea.

I'm reminded of the 23ft Penn Yan that dad had when I was young. that was a tunnel drive arrangement so way worse I know...but it was a nightmare handling in close quarters so I don't get it. I think I'd much rather have an outboard or I/O for a boat this sort of size

 

[rslifkin]

To me, the choices are inboard or outboard. I/Os are piles of junk that I'd have a rough time accepting for free. Too many failure points and with the engine jammed against the transom, they're hard to work on too.

An inboard or I/O setup gives you the option of powering it with a small diesel if desired. And if you plan to use the thing a lot, especially in salt water, a proper inboard with closed cooling is likely to be the most durable and longest lived configuration. Plus you get a clean transom for a swim platform or fishing without worrying about an engine or drive being in the way back there.

There's a guy locally with one of the 23ft Mako inboard center consoles. Not only is it a very well liked boat, but without the giant outboard stuck on the back, it's a whole lot better looking than most other similar size center consoles.

 

[toocoys]

I think I'd much rather have an outboard or I/O for a boat this sort of size

I've owned all three, and from personal experience, shafts are the way to go.

-They're cheaper to maintain
-They're cheaper to repair
-They're easier to work on
-They suffer the least corrosion, with a closed cooling system of course.

 

[Turtle Blues]

Got a yard full, how many do you want?
I/O absolutely at the bottom of the list as far as the mechanicals, bellows, and having to work on it. Bravo racing drives are pretty sexy though.



OBs are always in the way on the fishing boats and I won't even start on the outrageous cost of multiples, but a 1/2 cavitation short leg setup is still one of the fastest per hp combinations.

Long term lowest cost of repair and dependability has to to to full IB along with the easy access off the rear.

 

[DavidM]

Inboards are simpler certainly. But the depth of the engine and drive train means a higher cockpit deck, plus they are heavy.

I/Os are generally crap as noted above. All of the disadvantages of a straight inboard, but none of the advantages.

For less than 30', outboard is the way to go. In the past outboards were fuel hogs, no more.

David

 

[toocoys]

For less than 30', outboard is the way to go. In the past outboards were fuel hogs, no more.

Now they're just money hogs. LOL Have you priced outboards lately? They're outrageous.

 

[psneeld]

There have been some very popular inboards under 30 feet. Usually open or downeast design.


The Chris Craft Dory, Pacemaker Wahoo, Shamrock 26..others too just those are the 3 I am most familiar with.



Granted, all older boats but like other classics, sought after by some.

 

[skyhawk]

I've never owned or even operated an IO but your points all make perfect sense about them.
And it's been a long time since I've done any fishing but yeah I can certainly see that clear stern as an advantage there

Ah, a Shamrock....many years ago when I was just a teen I remember going with dad to look at and test drive a Shamrock. that was when he ultimately bought the Penn Yan. My guess is that the Shamrock would have been a much better boat even if not the better deal.

that tunnel drive was horrible...bad low speed handling and top heavy poor stability
but a more traditional inboard for a boat that size still seems to me to be not worth whatever advantages...doesn't appeal to me....
draft, poor low speed handling, potential for leaks at the shaft seal...

 

[Mako]

Now they're just money hogs. LOL Have you priced outboards lately? They're outrageous.

Simple solution... slow the heck down. A moderately sized single outboard engine. Do you really need to go 45+ knots? How about powering for a 20 knot cruise?

So absolutely agree with most comments above: an outboard for <30ft for a "normal" boat, then an inboard diesel for larger, then use the I/O as an artificial reef.

 

[toocoys]

Simple solution... slow the heck down. A moderately sized single outboard engine. Do you really need to go 45+ knots? How about powering for a 20 knot cruise?

So absolutely agree with most comments above: an outboard for <30ft for a "normal" boat, then an inboard diesel for larger, then use the I/O as an artificial reef.

The 75hp Yamaha starts at $10,000.

Yamaha Outboard Price List

So yeah... even “moderately sized” outboards are outrageously priced, especially when you consider you can buy a brand new 5.3L V8 for 5 or 6 grand.

 

[rsn48]

Power preference is regional and usually for a reason. Full disclosure I have an I/O.

In the Pacific Northwest, cruising from location to location is more a reality than anywhere else pretty much on the North American continent. One of the big deals is having a dinghy. Being on the hook is much more an option here and with it the dinghy is your "family" car. You use it to explore, fish, supplies to the mother boat and visit neighbours. I have seen all manners of dinghy substitutes up here from towed canoes, solid kayaks, inflatable kayaks, and a host of older solid dinghies.

Swim platforms are the traditional residence of a dinghy. Of course on larger boats you can have a crane system which is not my favourite, think elevated wind and waves. There are boat manufactures up here and they have definitely taken note of the outboard craze on the east coast. But the dinghy becomes the issue. Aspen is a well known power cat in our waters and they have recognized this problem and have begun to create dinghy design storage systems for their boat. Also Cutwater and the like in the dilemma, outboard but where do you put the dinghy?

I am an old fart and don't want to struggle with putting a motor on a dinghy hence I use the Seawise Davit system. I know over a certain weight you can have problems with this system but it suits many of us well. This system stores the motor and dinghy in one pull up, the motor separates from the dinghy and remains stored beside the dinghy.

Fisherman up here gives two twits about dinghies, they've been outboards all the way since Jesus was in diapers.

On the East coast, particularly places like Florida with few nifty islands to go to, who needs a dinghy. I have watch the Haulover videos and I've yet to see one boat with a dinghy on the back or above. Florida is more a go out for the day or so and come back kind of boating experience hence many more bow riders and center consoles than you will find in Washington and BC. And in Florida, my conclusion is you don't have a real boat unless you four or more outboards on the back all colour coordinated to the boat colour. I have never seen this once in BC.

Now to switch locations, I watch a channel that only shows photos and videos from around the world under different themes. I have watch a few of the canals in Italy. And to my surprise there are very few outboards, most have I/O's or shaft driven boats. I'm not sure why that scenario has evolved there.

So I see you are out east - go for the outboard.

 

[Nomad Willy]

David M wrote;
“For less than 30', outboard is the way to go. In the past outboards were fuel hogs, no more.”

It may be … or may not. IMO
It would require modern or new OB’s to have freshwater cooling that I don’t think they have or some other means of controlling the corrosion problems that have always been.
Gas engines need to have a cooling system that will allow operate at 180 degrees f. I think OB’s operate at 130 degrees. I think that w/o the hotter running the cylinder walls would perform the service of a large heat sink and that has in the past put a huge dent in the fuel efficiency of four stroke OB’s.

Is there something new in OB cooling systems? I love outboards but ??

 

[Mark P]

Well, I need to chime in to defend the I/O. I had a couple, both fresh and salt water - only Mercruiser experience. A very stable platform because of engine torque, lower rpms, and props are deeper in water. Big advantage is ability to trim outdrive up in case you wander aground - ask me how it worked &#55357;&#56833;. The issue of maintenance is fair - more in saltwater than fresh water but still not bad. Figure 2k per year on a 350hp Bravo3 which is about what I spent with it in salt 24-7-365.

 

[tiltrider1]

Everything about a boat is a compromise. Since most people on this forum are oriented towards slow long distance travel, inboard diesel will be the preference.

Fisherman seem to be in a hurry to get to the fishing grounds and then they want maximum open space for fishing from. No surprise they gravitate to outboards.

Lake boaters need a combination of space, speed and tilting for trailering. It’s easier for the builders to build the boat around an I/O than build for an outboard. The cost of a diesel is a no go with this crowd. There is an argument that the long run cost of purchasing and maintaining an outboard is cheaper than an I/O. However, people buy a boat based off of purchase price and rarely figure in long term maintenance. This is why lake boats are mostly I/O.

 

[psneeld]

Not sure about the builders favoring I/O over outboard....when I worked for Sea Ray 2000-2003....most every model for years was an I/O....withing a decade or so, I noticed most new small Sea Rays were an outboard versus an I/O.


Seems like outboards have dominated many markets in the last 10-15 years back East at least. Even 30-40 foot boats that used to be diesel powered have gone the way of outboards.

 

[toocoys]

I do have to say though, lately there’s been a wave of “cabin cruisers” around here with outboards though. And I’m not talking Sea Rays with a cuddy cabin. I’m talking 30’-40’ hard top, deck salon, lower berth type cruisers with two, three, or four outboards.

 

[Fish53]

Funny, I had the impression this was a "trawler" site?

 

[rslifkin]

Funny, I had the impression this was a "trawler" site?

It is, but plenty of us here own boats that wouldn't qualify as a trawler, but mostly get used similarly to the trawlers on here.

 

[Fish53]

It is, but plenty of us here own boats that wouldn't qualify as a trawler, but mostly get used similarly to the trawlers on here.

Yeah, I get that....

 

[psneeld]

Fish, what length is your smaller vessel (the one you posted in the riding sail thread)?


That's a pretty good example of a smaller inboard. Care to share your thoughts on its pros and cons as an inboard vs outboard?

 

[Fish53]

Fish, what length is your smaller vessel (the one you posted in the riding sail thread)?


That's a pretty good example of a smaller inboard.

It's 26 feet with an 18hp diesel, and a bit of a rarity in that it's a less than 30 foot full displacement hull that isn't a sailboat.

 

[lwarden]

I've owned all three, the last two boats prior to our Lindell were Shamrocks, a 26 and a 20 cuddy. We also currently own a Mastercraft inboard ski boat. I like the simplicity of the shaft drives and am a DIY guy so find the inboards easier to work on. The best attribute is a clean transom for fishing, and swimming off. In general, I think they are just cooler rigs and more unique. The negatives is they are slower and probably a bit less fuel efficient than todays 4S outboards. Shamrocks have a bit of a cult following and a strong user base online. In fact I found the Lindell brand through one of the Shamrock members in the PNW who made the suggestion.

Other notable inboards of the Shamrock style were some Makos, Fish Nautique and Albermerle.

I wouldn't own a I/O ever again, especially not a Volvo. I still have nightmares about that setup.

 

[BandB]

I/O's obsolete. Instead of the best of both worlds, a bit of the worst of both.

Outboards, performance, easy to replace, performance, initial cost for similar hp.

Inboards, long term durability but without the speed of the outboards on similar boats.

To serious fishermen, there are other issues like trolling valves for trolling speed and the sounds conducive to fishing and freeing up internal boat space plus for those who trailer, there is weight.

If I intended to own it seven years or less, outboard all the way. More, would be inboard, but then I'd want a bigger inboard than would likely fit, for speed.

I checked into Seavee's 39' a few years ago when it came in all configurations. The only one I would have considered is the outboard version. The better performance and speed was just too much to turn down. I know this isn't the emphasis of most here but it is for a 25' or a 50' Center Console.

If you want trends, just go to Sea Ray's site and see the 35-40' outboard runabouts.

Under 40', outboard.
40-60', match to use.
Over 60', inboard.

Of course we omitted pods which is a whole different subject especially in the 40-70' range.

 

[skyhawk]

David M wrote;
“For less than 30', outboard is the way to go. In the past outboards were fuel hogs, no more.”

It may be … or may not. IMO
It would require modern or new OB’s to have freshwater cooling that I don’t think they have or some other means of controlling the corrosion problems that have always been.
Gas engines need to have a cooling system that will allow operate at 180 degrees f. I think OB’s operate at 130 degrees. I think that w/o the hotter running the cylinder walls would perform the service of a large heat sink and that has in the past put a huge dent in the fuel efficiency of four stroke OB’s.

Is there something new in OB cooling systems? I love outboards but ??

I don't understand that at all..... I have no knowledge/memory of what any outboard that I've ever had operating temp was in terms of degrees....
but I do know that they have a thermostat. I'm quite confident that if they needed 180°F, then they'd put in a 180° thermostat. Seems easy. What am I missing there?

 

[rslifkin]

I don't understand that at all..... I have no knowledge/memory of what any outboard that I've ever had operating temp was in terms of degrees....
but I do know that they have a thermostat. I'm quite confident that if they needed 180°F, then they'd put in a 180° thermostat. Seems easy. What am I missing there?

Raw water cooling is the problem. You can't run it much above 150 - 160 or you get very rapid salt buildup and/or corrosion issues in the cooling system. Plus raw water systems aren't pressurized, so you need lower temps to avoid boiling in the hottest parts of the cylinder heads and such.

That's why traditionally, inboards had 2 different temp thermostats. A colder one for raw water cooling and a warmer one for closed cooling.

 

[psneeld]

The remedy for the salt buildup as recommended by everyone is a thorough flush after every run...thus the fancy water flush options on modern outboards.


Just because the thermostats open at cooler temps doesn't mean the engine runs at that temp.

 

[rsn48]

The new Merc I/O engines are fresh water cooled and are not as corrosion prone as their old engines and all the other manufactures I/O engines.

 

[rslifkin]

The new Merc I/O engines are fresh water cooled and are not as corrosion prone as their old engines and all the other manufactures I/O engines.

In general with an I/O, I'd be far more worried about drive corrosion than engine corrosion.

 

[Bob M]

I've owned all three: inboard (37 ft), I/O (27 ft and 17 ft) and outboards (21 ft and less).


Given the choice on a trailerable boat, I'd choose the outboard. I live in a climate where winterization is a consideration and an outboard requires basically nothing to winterize it. Like the I/O, the outboard has trim and can operate in much skinnier water than an inboard. If I need to re-power, it's a lot less expensive getting this job done with an outboard than an inboard and repairs are often less expensive with an outboard because the mechanic doesn't have to stand on his head to work on things or pull the engine to get at something.


I've had no trouble selling outboard engines when I've no longer had use for them, and for considerably more than I expected to get for the engines. Recently I sold a 40 hp 2 cycle Merc and a 50 hp 2 cycle Merc. They both sold the first day.

 

[psneeld]

I might argue that some inboards might be cheaper to repower/work on rather than an outboard depending on who does the work.


Too many what ifs....narrow down to specifics and I think it can go either way.