Conference vicki::boats

    Rick, I'll take a stab at this one.  I've never read of an aluminum
    inboard in any of my "Classic Boating" mags, at least not in the 
    runabout size range.  My guess is that an aluminum hull, unless very
    heavily reinforced, would flex too much to be acceptable from a prop
    shaft alignment standpoint.  If heavily reinforced, then there
    probably wouldn't be a significant weight savings over fiberglass.
    Hanging an outboard on the back of an aluminum boat causes no problems
    when flex occurs.  
    BTW, there are larger aluminum boats with (I assume) inboards mainly
    manufactured in the Northwest.  The ads picture them as crashing thru
    the surf out there so they must be pretty rugged.  I imagine that the 
    longer distance available before the prop shaft exits the hull allows
    for enough play to avoid problems.   
    One more thing.  I would think that lightness in a ski boat might not
    be considered goodness.  I would think that if you were to cut hard
    enough, you would effect the straight line tracking of the boat if it
    was too light.
    Just a thought.
    Wayne  

Interesting concept.  I stopped by Tri-City Marine in Lunenberg last
week, where they've just taken on the Sylvan boat line, and have a 
ton of them in stock.  Sylvan is one of the larger mfg'ers of aluminum
boats, but their tournament ski boat, called SkiTastic is made of 
fiberglass.  Of all people, if they thought an aluminum ski boat was 
feasible and marketable, I'm sure they'd have done it.

Some of the problems I see with an aluminum ski boat are weight (*too*
light), styling, hull design, and consumer acceptance.  To some extent,
weight in a ski boat is good.  A 17' aluminum hull can be made to weigh
no more than a few hundred pounds.  Even fully rigged, the boat would
be so light that a strong skier would probably yank it around pretty
good.  Also, fiberglass can be molded into infinite shapes, with strakes
and chines in any design you want, making it much easier to perfect the
hull design for skiing.  The shape of aluminum hulls is somewhat limited
by the material, making it harder to design and build the ideal hull shape 
for skiing.

Lastly, is the issue of styling and consumer acceptance.  It ain't gonna 
be built if it won't sell, no matter how good an idea it is.  Most of 
today's aluminum boats are generic looking fishing boats.  If you want 
"utility" you go with aluminum; if you want "sporty" you go with fiberglass. 
A reputation like that is hard to shake, and I doubt one company can change 
that image on its own.

It wasn't always this way - my current "family" boat is an aluminum 15' 
1954 Feathercraft with double cockpit and barrel stern.  It has styling that 
would shame most fiberglass boats made today, and is also solid as a rock.
I don't think that "flex" is a problem as Wayne mentioned - a welded gridwork
of extruded aluminum ribs is stronger that anything that can be made of wood.
My Feathercraft is the strongest and most flex-free small hull I've ever 
ridden in, despite it's nearly 40 years of existence.  It has round chines 
and a fairly flat bottom however, so is not ideal for skiing.  Then again, 
based on the number of ads you see for 15' 50hp "ski boats", I guess almost 
anything qualifies...   8^)

Rick

    Come to think of it I have never seen a small < 18 foot aluminum
    inboard.  I agree with you Rick, I doubt that flex is the reason
    for not seeing them.  Must be due to styling and cost factors vs.
    fiberglass.  Any other thoughts on this?
    
    Jeff

    Those pictures you see in magazines, are most likely Striker.
    
    They make 40+ ft. boats with straight inboards. I've seen several
    40's and its hard to tell that they are alum. They do a darn good
    job of it.
    
    But i don't think i would want an alum in the salt. There are
    a whole set of different problems that come with it.
    
    In the fresh, may be no problem.
    
    
    So why an aluminum ski-boat?????????????
    
    JIm
    

    
    Why an aluminum ski boat?
    
    Well, as I was pondering my navel (rather than skiing, damn Winter!)
    it ocurred to me that HP/weight ratio appears to be the main factor
    in performance and if a lighter ski boat could be built which would
    still track well then many other factors would improve. ie: Fuel
    economy, top speed, acceleration, SMALLER Wake.
    
    It was very interesting that a "aluminum" boat builder chose to build
    their ski boat in Fiberglass. Admittedly, fiberglass would be easier
    to design specific hull features into for the ultimate wake
    characteristics, but I would think that most of the same features
    could be built into Aluminum, would the design cost be too high?
    
    Rick
    Already_suffering_from_skiing_withdrawals_it's_only_been_a_few_days
    
    I'm still not sure what the difference is in weight... 2 to 1? Of
    course I'm sure a majority of the weight in most skiboats is
    the "plush" interior amenities. :-)
    
    
                                                  

    One of my older issue WaterSki mags has a short article on an aluminum
    skiboat although I think it's intended as an outboard setup. It's made,
    or to be made by either Starcraft or Alum-Weld, or summin like that.
    So someone has thought of it though not with an inboard. 
    
    I don't see fabrication as an issue as you can bend/extrude/shape
    aluminum fairly easy. My fiberglass inboard has the perfect hull, :^),
    and it could be fabricated from aluminum though I'm sure the cost of
    equipment would be greater. Consider some of the compound curves on older 
    car bumpers and aluminum is a walk in the park by comparison.
    
    I would lean towards the 3 possible reasons. 1) An aluminum boat would
    be esthetically ugly and plain in comparison to 5 color in_mold gelcoat
    fiberglass. 2) The lightness of the  overall package would not lend itself
    well to directional stability even with tracking rails and fins. 3) I
    would think that an aluminum boat with an inboard would be noisy in
    comparison. 
    
    None of the outboard tourney boats track as well as the inboards, they
    are lighter, the ski pylon is taller to clear the engine, and they
    don't use tracking fins as much ( 1 or none vs. 3 for an inboard). 
    I wouldn't buy a lot of stock in a company whose sole product is
    aluminum ski boats, inboards or outboards.   
    
    
    ~jeff_who_loves_his_fiberglass_inboard

    Let's try it!  Here's the plan.  Rick S., you donate the drivetrain out
    of your ski boat.  Rick W., you donate your AlumiCraft (I saw it. It is
    a beautiful boat!!).  I'll donate the garage and my time  (my wife
    didn't really think she'ld get to put her Bronco in there for the
    winter, did she?).  We should be done by spring.  I bet the thing would
    fly!  And I do mean fly!  We can call it a "AlumiCraft Nautique"
    Let me know when you want to get started.
    Wayne

    re: .7
    Actually, my boat is a "Feathercraft", making the finished product 
    a Feather-tique.
    
    I know, it sounds like it should be marketed by Victoria's Secret.
    
    Rick

    Upon further thought, I think that we would also be forced to do away
    with any seats in the boat because there wouldn't be enough room so
    we'll have to design a tow rope/control cable so that the water skier
    can control the boat.  Of course that will put us back to the
    discussion about how does the observer law apply to those remote
    controlled personal watercraft designed to just pull a skier.  Maybe
    we'll have to do a radio controlled boat and hope it doesn't get out of
    range of the transmitter!
    Boy, you can tell that the boating season is over when the only
    activity in the files is discussions like this one!
    Wayne
     

re: .9
>> Boy, you can tell that the boating season is over 

It is?  Sez who?!!!

    Assuming interest in this discussion isn't yet dead...;-)
    
    The main reason smaller production boats are offered in aluminum is
    expense.  While tooling fiberglass molds is very costly, the
    incremental expense of turning out hulls is very attractive, and if you
    plan to sell more than 50 or 100, the tooling costs are easily
    amortized over the production run or lifespan of the molds.  
    
    For sailboats, at least, the main advantage of aluminum is phenomenal
    strength, less in absolute strength than in elasticity.  It will deform
    incredibly to absorb shock before failure, much moreso than stell per
    pound, for instance.  Above about 35' LOA aluminum hulls weigh less
    than equivalent fiberglass and are much stronger.  (For steel, that
    trade-off occurs perhaps closer to 45' due to greater weight for
    weldable panels.)  Aluminum is certainly more expensive for many
    reasons, up to meag-yacht size, when who cares anyway.
    
    Winninghoff Boats of Rowley, MA makes a wide range of very seaworthy
    outboard and inboard aluminum boats, 22' up to perhaps 70' LOA, which
    are rugged and capable.  The USCG has bought a couple.  They are not
    ever confused with consumer-designed gelcoated sportboats, however.
    
    John.