10.8 International - cruise speed & economy

[christur]

Hi all -

I'm looking at a 10.8M international, and have some questions about average cruise speed & economy for the 454 gas powered boats. Specifically, I'm looking for tables that outline RPM, KTS and GPH across the whole range, as well as what is the RIGHT cruise speed in your experience. I'm sure there are a lot more F36 owners out there, so would love input on that as I'd expect the numbers to be similar between the 10.8 and the F36.

Thanks!

Chris

[RWS]

The F series has an entirely different hull design than the International series.

For more information take a look at

http://sites.google.com/site/trojaninternational/Home

David Pascoe did a review on the 10.8, it's worth a look

http://www.yachtsurvey.com/boatreviews/ ... 8meter.htm

Here's the actual results on my own International series 10 meter express with 454's and 4 blade 18x19 props. Engines were beginning to get a bit tired.

These numbers are fully loaded, 40 gal water and 150 gal fuel. This is a a fully optioned express cruiser, genset, icemaker, wetbbar, etc.

This boat has 12" tabs with drop fins vs. the factory flat 9" units.

This boat does not have the wind resistence the 10.8 does.

If you are not getting 4400 WOT on the 454, something is wrong. Could be as simple as a dirty bottom, or some barnacles on the props.

Also, the mid cabin series has a different engine location, gear reduction, prop angle and prop size than the express cruiser. This issue has previously been discussed on this forum at length.

RWS

[christur]

Thanks for the info RWS, I've found that info before and have been pouring over your info recently.

I've tried search, but haven't found much other speed / economy on the international series (besides yours) yet, and none on the 10.8. Maybe I'm not searching effectively. Lots of good info on the F series but as you indicate, the hull is completely different. The only 10.8 stat was in one of the review articles, but it seemed completely bogus (something like 6GPH @ 18 knots or somesuch nonsense).

Thanks for the links, David's review is full of praise, but doesn't mention speed / economy and the site (while interesting) doesn't either.

Do you think the F seriies would be better or worse economy vs. the delta conic hull?

Chris

[RWS]

It all depends on what you are trying to accomplish.

Fuel costs are not as big a percentage of annual costs as you may believe.

Factor in insurance, dockage, scheduled maintenance, bottom work, repairs and unscheduled surprises and depreciation and it all will come into focus.

Risers, elbows, raw water pumps, it's all much more than belts and spark plugs.

You are looking at boats 25 years old and older. The trick is to repair rebuild and replace before a system or component fails.

You do not want to be stranded on the water.

Many people leave this hobby every year because they are not able/equipped or financially fortunate enough to deal with these issues properly.

My own best numbers with the 454's were 18.5gph 15kts @ .81nmpg

The 10.8 connvertible has additional waterline wetted surface area, increased weight and windage which will probably keep you somewhat below those numbers.

Most of us here on this forum do our own maint & repair, translating into allowing us to afford much more boat than we otherwise could afford.

The 10.8 is a great boat, however it needs to be the right fit and match for the owner. You might be better served with something smaller/lighter/newer that one of these Internatonals who's size and beam alone creates a demonstrated appetite for fuel which combined with the age, cost and frequency of repairs could make you an unhappy owner.

RWS

[ready123]

In my experience prospective/existing boat owners who worry about fuel costs should buy a cottage.
I agree with RWS that fuel is a small part of the yearly costs.... my mooring alone is always more than the fuel no matter how many long trips I take....

If fuel cost is a worry then boating might not be the pastime for you.... to run a power boat one should be prepared to spend a couple thousand dollars on fuel alone and make sure one has at least that yearly for maintenance and the same or more for dock/storage.
In my view if one does not have $7K/yr available for boating then one needs to look at a smaller boat or another hobby.

[alexander38]

I have to agree my boating bill came to $8400.00 dock fees, gas, and repairs and one unwanted haul out to replace a sea-cock, This year we're taking a two, 2 week trips in the summer and fall and setting a boating budget of 10K.

[Wes]

I'd love to keep our annual expenses under 10K. I figure ours at between 14K and 18K. Of course our marina runs 7K for the year. This last year was expensive on the fuel side since we traveled almost 1200 nautical miles.

[foofer b]

$7000 for the marina. Ouch. How much is that per foot?

[Wes]

We're in a 40' slip that runs (round figures) 5600 and then 1500 for winter storage. We are a 10 meter - 33'. I could be is a smaller slip but I like the extra room aft and on the port side.

[prowlersfish]

Hi all -

I'm looking at a 10.8M international, and have some questions about average cruise speed & economy for the 454 gas powered boats. Specifically, I'm looking for tables that outline RPM, KTS and GPH across the whole range, as well as what is the RIGHT cruise speed in your experience. I'm sure there are a lot more F36 owners out there, so would love input on that as I'd expect the numbers to be similar between the 10.8 and the F36.

Thanks!

Chris

The hull shape of the 2 boats are night and day you may as well compair with a sea ray or a bay linner

The fuel is the cheapest part of owning a boat

[christur]

The hull shape of the 2 boats are night and day you may as well compair with a sea ray or a bay linner

The fuel is the cheapest part of owning a boat

Thanks everyone for the warnings & comments on boat ownership economics, but I'm very aware of what we're getting into. Heck, the boat we're looking at will need a re-power soon, so we're budgeting for that time and $. 100% agree - gas is only a fraction, etc etc etc.

Still interested in answers on 10.8 convertible KTS / RPM / GPH. RWS posted info that is the closest (thanks). Not because I'm concerned about affordability, but to compare with the boat we are looking at because it seems way off.

Chris

[RWS]

Chris,

If you repower a 10.8, you will really have something.

Here's my info with the diesels

RWS

[JuiceClark]

I just happened to see this boat with a seatrial video for sale in my area. It needs a little tuning...think max should be 4400 rpms not 4000.

http://www.youtube.com/watch?v=riZQAKC8wrw

[captainmaniac]

RWS - I hope you have a problem with your chart... if you are going through 60 gph at 1800 RPM / 10ish knots its time to look for a hole in the tank!