just getting starting but a question

Just started looking at boats in the 36 to 32 ft range.

I Like Island Gypsy, Mainstay, Grand Banks and Ranger tug, so far.
Some priced under $75k.

If the boat has twin diesel engines and you are going at a
slower pace. Can you just run 1 engine to save diesel?
Do 2 diesels running at slow pace burn 2X the gas or does
the one running work twice as hard.

Thanks for any help

If you use the search link at the bottom of my post, you'll find a plethora of discussions about that very topic. Grab some popcorn before you start...you've got a lot of reading ahead of you.

if and when the gas engines get old, can they be
replaced with diesels engines, or this just impossible?

I know the cost would be high.
I'm watching a 42 ft Bluewater and it looks like a very nice
boat, but the engines are gas and I know most people
on this forum prefer diesel.
Thinking of trying the loop and later wintering in FL from Iowa.

Thanks

if and when the gas engines get old, can they be
replaced with diesels engines, or this just impossible?

They coukld be but it would be a big looser.

Most gas engines are in faster boats that have zero ocean pretensions.

A 300hp gasser is pretty cheap ,as a brand new crate engine

300hp diesels would weigh 2x or more and cost 3-5X as much .

There are few displacement gassers in GRP , but yes it could be done .

The rational to do it is not undrestandible tho.

Diesel costs more , way more for maint and is far louder than gas.

A 45 ft displacement boat will probably cruise at 60 hp ,,,5 GPH on gas at worst and 3 or 4 GPH at very best in diesel.

At perhaps 200 hours a year , you do the math.

With no ocean crossings in mind the gas will be cheaper and easier to live with

I'd suggest finding a boat with what you want engine wise and sticking with it. Trying to retrofit an old boat will likely not be very cost efficient. Also, most boats in the range you are looking at (32 to 36) will be single engine.

In addition to the cost of the engines themselves, the transmissions and running gear needs to be replaced in most gas to diesel conversions. Diesels turn slower with more torque to provide the same power that a gas engine would with higher rpms at less torque so the prop shaft diameters usually have to be increased to support higher pitch and larger diameter props. So new props, new struts, new cutlass bearing, new shaft log, new stuffing box and hull work to accommodate it all.

I have a headache. You are looking for a 'cheap' 32-36' boat. But fixate on a42'. Okay. They are nice boats. But...

I'll share what I learned looking at them. Blue water 42's.

First off; I was looking at them when the economy was really in the tank. They had two distinct production runs. Pre 1993. And post 1993. The boats Pre '93 are prone to bottom delamination, poor stringer construction and no aft end access. And use balcor.

Post '93 they switched to a different hull layup facility that corrected the issues. And went to airex foam core.
But. You will see the prices from 'before and after' reflecting this. (Now you know why.)

I gave up because I found out I couldn't get a mooring to fit a 42' anything for a reasonable price in Cape Cod. Slips are outrageous. On the order of 7500 to 10k per season. I still love the flush deck salon, and the huge flybridge. But can't fit one into my locality.

A mechanic on another forum affectionately called them: flexible flyers. The bottoms flexed so much!

I opted for a solid glass single engine trawler. Diesel.

People here prefer diesels for many reasons, probably covered here many times.

If you plan to cover ocean distances, diesel reliability and economy is important. Talk to mechanics or owner/mechanics. Look for reliable engine recommendations. Pick a boat with those engines. If money is tight, pick an older boat with the right engines if you're handy.

I have a big, older boat that would burn 20 gallons an hour with most engines at the speed (10 knots) I prefer to run. Instead, because of the Detroit engines I burn 8.5 gallons an hour. No repairs at all in the last 5 years. No injectors, no fuel pumps, no water pumps, not even impellers.
I prefer twins because of handling and backup. They make docking easy. Twice, 35 years apart, I have come in on one engine. Both times because of crab pot buoy lines some a-hole tossed overboard. I didn't want to dive in 50°F water to clear the prop. Twins do not use twice the fuel at reasonable speeds. Using one engine I get 40% of speed with half the fuel. I could get better economy, but prefer 10 knots.

Lepke said:

No repairs at all in the last 5 years. No injectors, no fuel pumps, no water pumps, not even impellers.

Click to expand...

No matter what engine you end up with, I'd suggest you change your impellers on a regular schedule.

Lepke said:

No repairs at all in the last 5 years. No injectors, no fuel pumps, no water pumps, not even impellers.
I prefer twins because of handling and backup.

Click to expand...

With that maintenance schedule, I would prefer the redundancy of twins as well.

Most of my main traveling will be from Clinton Iowa on the Mississippi
down the Tenn Tom to winter in Fl. So some fresh water and salt.
Around 1500 miles one way.
The reason I am asking about a 1986 Bluewater 42, with twin gas engines,
it is for sale in my marina and appears well maintained. Price mid $50s
Also it drafts less than 3 feet, which is helpful on the river for summer use.
I can see this boat, ride in it and probably stay overnight if I asked the
owner for a trial .

I have no trawlers in this area and other than surfing Yachtworld or
boat trader, no way to conveniently check them out.

The survey is 4 years old, should I get a new one?
250 gal of gas, best guess, range in miles at a 7 kn speed?

dhays said:

With that maintenance schedule, I would prefer the redundancy of twins as well.

Click to expand...

He did mention he has Detroit's.
The only serviceable part would be the impeller. Pumps are all gear driven unless he's running 300 plus hrs a year in a salt environment he's probably fine. With the exception of the impeller.
I'm in fresh water and only average 50 hours / yr . Change my impellers every 3-4 years.

I have neighbors with Bluewaters as you describe and they seem to like them. One took his from Memphis to New Orleans and then back up the Tenn Tom, so it's fairly capable. To me, its a houseboat with a pointy bow, but it has lots of room on one level if that's what you're looking for. When buying a boat, I'd always get my own survey from the pickiest surveyor I could find.

You aren't that from from the Great Lakes, which is a great place to find freshwater boats. I'd suggest walking on several different types of boats before you just settle for the one for sale nearby.

If the boat you like most has gas engines, then go with gas engines but don't plan on trying a change to diesel. For Loop boating, for inland river cruising, for short hop coastal cruising, there's nothing horribly wrong with gas engines. We lived on an inland lake. I had 30 years with gas engines before ever seeing a diesel.

ctbarbarian said:

Most of my main traveling will be from Clinton Iowa on the Mississippi
down the Tenn Tom to winter in Fl. So some fresh water and salt.
Around 1500 miles one way.
The reason I am asking about a 1986 Bluewater 42, with twin gas engines,
it is for sale in my marina and appears well maintained. Price mid $50s
Also it drafts less than 3 feet, which is helpful on the river for summer use.
I can see this boat, ride in it and probably stay overnight if I asked the
owner for a trial .

I have no trawlers in this area and other than surfing Yachtworld or
boat trader, no way to conveniently check them out.

The survey is 4 years old, should I get a new one?
250 gal of gas, best guess, range in miles at a 7 kn speed?

Click to expand...

We have a 47' 1982 Bluewater coastal cruiser with gassers. We originally wanted Diesel engines but at the end of the day, for what we are realistically able to use our boat for at this stage in our lives, the gassers will do. The boat ticked off most of our must haves and we love it.

Personally, for your use, I see nothing wrong with gas engines. Repairs, maintenance and replacement (if necessary) will be significantly cheaper. Fuel availability will not be a big problem. You'll be running the boat enough to keep the fuel fresh. Operations costs will be comparable. I don't see any down side.

ctbarbarian said:

...The survey is 4 years old, should I get a new one?...

Click to expand...

Yes, a lot can happen in 4 years. Get a mechanical survey too,especially check the safety aspects of the fuel system.

Cappy
Your right on the pre 93 BlueWaters. I bought my boat knowing the stringer were bad and I changed all of them. Had a mill make the correct size for ea. and set them in fiberglass.