The useful life of traditional,
diesel, inboard
propulsion systems --
engine,
transmission, shafting,
propeller -- is often given as around 10,000 hours, as a
rule of thumb. Many installations make it longer than that, a few fail early. After these systems reach end of life, usually the
boat is either repowered or scrapped.
In another thread, the useful life of one particular
saildrive was quoted as being 2,000 hours. Anecdotal evidence suggests that this is not unusual. Saildrives are derived from
outboard motors and stern drive systems, and neither of these ordinarily last much longer than 2,000 hours; saildrives themselves have been part of the
boating landscape for many years and have never enjoyed a reputation for longevity.
The trend, of course, is towards saildrives. No one buys a new sailboat with the intention of putting more than 2,000 hours on the auxiliary. The powerboat market accepted the short life of stern drives and outboards long ago in exchange for the benefits they offer in speed,
fuel economy, upfront cost,
interior layout, and weight distribution.
In the stern drive market, there are at most a dozen or so major outdrives and volumes are high enough that margins have thinned out and costs have come down. The savvy owner of a stern drive
boat can
purchase a lower unit over the counter for under $1000 or an entire outdrive for around twice that in most cases. In many cases there are local stocking dealers, and once the boat is out of the
water,
installation is straightforward, taking only a few hours.
Is there similar hope for saildrives? Can we expect to see a future with a handful of standard sizes from two or three manufacturers, with ease of replacement of the entire assembly as a design goal? Can the long-term
reliability and lifespan of these systems be improved? Does anyone think that direct-drive inboards will remain an important part of the
new boat market over the long term?