In 30 years I have never heard of anyone dying from carbon monoxide poisoning
with diesel engines, diesel has less than 10% of the carbon gas has, I have
heard of people feeling sick once or twice, but it is not near as deadly as
gas engines. That is why ABYC, NMMA, and CE, require CO detectors on any
gasoline installation and not diesel. Equally Bob is right about the exploding
part.

I am sure the need for air conditioning in the pacific N.W. is not very high,
and you can go with a DIESEL forced air heating system which is clearly
another reason for diesel power. But you couldn't give one away without it
here in Florida. Just air conditioning is fine if you go from marina to
marina, but if you cruise and anchor you will need a generator. The retail
cost of a Next Generation Power 3.5 kw generator (160 lbs) with sound shield
is $6000 plus install, and it would easily power the air conditioning and
other needs on the smaller cat.

Of the almost 100 Manta catamarans I have sold 95% went with ac and a
generator on purchase, and 4% of the remaining 5% came back and retro'ed them
after a year of cruising. "SIMPLE IS AS SIMPLE DOES". People don't like to
sweat while they sleep at almost any price.  Side note:  Back in the 80"s my
brother had a 33 ft sailboat in which he installed a 4kw diesel generator my
father made called the DESI which at the time was the smallest 4 kw in the
world, and a 12000 btu air conditioning. When he pulled into anchorages and it
was a hot muggy, buggy, rainy night, owners of 50 +footers, who didn't have it
would dinghy over and beg him to let them sleep on his salon floor, pretty
funny.

I think it is hard to generalize when it comes to the cost of adding options,
since what "base price" includes varies from builder to builder. On average
the customer spent 35% on options for Manta's over the years. These were very
complete boats with generator, air, solar, refrigeration, washer/dryer,
complete electronics, water maker, windlass, dinghy, extra sails etc.

Manta grouped options into "pac's" to streamline the commissioning process,
and help the customer understand what the true realistic "bottom line" would
be. We had to do it this way because no one was selling complete fully
outfitted boats at a fixed price, everyone was using the loss leader way of
selling with a "base price". Just this year on my recommendation Manta has
made the move to selling completely outfitted boats, turn key for a fixed
price.

Based on over ten years of experience they know what 99% of the owners are
going to want, and I think the market has finally matured and become
sophisticated enough to understand what the difference between "base price"
and fully equipped, and ready to cruise boat is. Back when the base price of a
Manta was 275k up to the last base price of 385k people could justify the cost
of diesel engines, generator, and air conditioning.

Final note I have never heard of ANY outboard going 2000 hrs. let alone 4000
hrs without major service, not even ones on dinghies.

Having owned a 28' outboard-powered cat for nearly ten years I have some
thoughts on the matter.

The advantages have been pretty well laid out previously and I agree with
them.  There are some disadvantages too:

Efficiency - A modern diesel still beats a modern 4-stroke by about 35%.
The price of diesel has climbed relative to the price of gas lately, so the
operational cost of the outboard is probably only 20% or so higher.  But the
effective range of a gas boat is still substantially smaller, which is a big
deal for those of us in remote areas.

Noise - the new common-rail diesels are amazingly quiet.  So are 4-stroke
outboards when they are idling.  But an outboard running at high RPMs is
still pretty noisy - I had to keep my cabin door closed when running or it
was hard to talk.  There are no effective ways to dampen noise on an
outboard, it's not like you can add sound shielding.

Weight distribution - hanging outboards off the aft transom(s) forces some
design compromises.  Boat design doctrine says that the majority of the
boat's weight should be as centered as possible.

Prop size - outboards are primarily designed for planing hulls.  Running at
slower displacement speeds suggests larger diameter props which can't fit
under the cavitation plate.  And the outboard's gear ratio is fixed, you
can't change the transmission.  Not to say that an outboard will never work,
just that displacement boats, even faster cats, is not the target market.

Vulnerability - All of your expensive propulsion system is hanging out there
ready to be rammed.  I lost an expensive stainless prop to an errant trawler
recently.  Also suffered a cracked cowling due to an unidentified encounter.

Maintenance - outboards should be easier, right?  And generally they
are...if the boat is out of the water.  But a Coastal Cat 34 is not the type
of boat you'll be hauling out very much.  Now you're doing maintenance with
the outboard suspended out over water.  Buy lots of cheap tools - you'll be
offering them to Neptune regularly.

Longevity - I concur with Pat.  I've heard of outboards making it over 2500
hours with 'ritualized maintenance', but no normal boater (including me)
will want to go through the processes these guys did.  1500 hours is a more
realistic number, which is still probably long enough for most.

Bob Deering
Juneau, Alaska

Maybe Yanmar should work on their outboard diesels and market them in the USA again?

-----Original Message-----
From: Robert Deering deering@ak.net
To: 'Power Catamaran List' power-catamaran@lists.samurai.com
Sent: Mon, 14 Apr 2008 11:47 am
Subject: [PCW] Outboards on a cat

Having owned a 28' outboard-powered cat for nearly ten years I have some
thoughts on the matter.

The advantages have been pretty well laid out previously and I agree with
them.  There are some disadvantages too:

Efficiency - A modern diesel still beats a modern 4-stroke by about 35%.
The price of diesel has climbed relative to the price of gas lately, so the
operational cost of the outboard is probably only 20% or so higher.  But the
effective range of a gas boat is still substantially smaller, which is a big
deal for those of us in remote areas.

Noise - the new common-rail diesels are amazingly quiet.  So are 4-stroke
outboards when they are idling.  But an outboard running at high RPMs is
still pretty noisy - I had to keep my cabin door closed when running or it
was hard to talk.  There are no effective ways to dampen noise on an
outboard, it's not like you can add sound shielding.

Weight distribution - hanging outboards off the aft transom(s) forces some
design compromises.  Boat design doctrine says that the majority of the
boat's weight should be as centered as possible.

Prop size - outboards are primarily designed for planing hulls.  Running at
slower displacement speeds suggests larger diameter props which can't fit
under the cavitation plate.  And the outboard's gear ratio is fixed, you
can't change the transmission.  Not to say that an outboard will never work,
just that displacement boats, even faster cats, is not the target market.

Vulnerability - All of your expensive propulsion system is hanging out there
ready to be rammed.  I lost an expensive stainless prop to an errant trawler
recently.  Also suffered a cracked cowling due to an unidentified encounter.

Maintenance - outboards should be easier, right?  And generally they
are...if the boat is out of the water.  But a Coastal Cat 34 is not the type
of boat you'll be hauling out very much.  Now you're doing maintenance with
the outboard suspended out over water.  Buy lots of cheap tools - you'll be
offering them to Neptune regularly.

Longevity - I concur with Pat.  I've heard of outboards making it over 2500
hours with 'ritualized maintenance', but no normal boater (including me)
will want to go through the processes these guys did.  1500 hours is a more
realistic number, which is still probably long enough for most.

Bob Deering
Juneau, Alaska

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