Diesel Boats vs Gas

As you may know, diesel engines aren't something
you should take lightly.  There are good reasons
why the rush to put them in cars back in the 70s
flopped.  Diesel isn't the ideal power source for
all applications.  

Engine speed
Diesel engines gained the reputation for long
service life early on in the history of the
engines, mainly from engines that were used in
commercial operations.  These were big, very
slow to turn engines that were usually in the
600 - 1,000 RPM range.

The long service life of the diesel engine isn't
really a myth when used in the proper application.
It's only a myth in pleasure craft, where the
engines are operated in-frequently at high and
low speeds, normally under very heavy loads and
adverse conditions.

Fuel consumption
If you plan to engage on some serious long range
travel, especially if fuel stops aren't available,
then fuel consumption will become an issue.  
Diesel engines will normally burn 1/3 to 1/2 the
amount of fuel as their gas equals.  Considering
the cost of the engines versus the amount of
fuel you'll burn during the time you own the
boat, fuel savings isn't really important.

Dilemma
Most questions of choice arise for boats that
are in the 28 to 34 foot range where either type
of engine is available with adequate horsepower.
Gas engines do have the advantage that they are
cheap to buy and also cheap to repair.

Diesel boats are just the opposite, as for the
price of one you could buy three gas engines.
For the price of a smaller in-line 6 cylinder
diesel, you can buy two gas engines.

Therefore, cost wise, unless you really need
diesel power, diesels aren't very practical.
The advantage to diesel comes only at the
point where the extra torque is needed because
a gasoline engine would simply be under too
much strain to have an adequate amount of
service life.

If you have a choice of gas versus diesel,
your first concern should be to determine
whether or not you can really afford to own a
diesel, as the initial price is only part of
the cost.  

If you simply can't afford to write a big check
for routine maintenance, then you will probably
be better off going with gas.  On the other hand,
if you have a lot of money, diesel would be
your best bet.  Diesel engines are great to
have, although they cost a lot of money to
up keep and they generally aren't the way to go
for those on a budget.