On Fri, 15 Sep 2000 09:17:09 -0800, Kent Lind wrote:

>> >They are very wet and not particularly comfortable on long runs.
>>
>>
>> This strikes me as odd, considering that I have frequently used RIB's
>> offshore without getting wet, unless it was raining.  The standard type
>> of rigid hulled inflatable, with a chined deep V hull, is designed to
>> be operated in a planing condition regardless of sea conditions.  The
>> practiced coxswain should have no problem doing this - to keep the
>> props in the water you need to take the power off for an instant at the
>> wave crest and then reapply power into the trough and up the face of
>> the next wave.  One hand on the wheel and one hand on the throttles at
>> all times - in a heavy sea you will be slamming the throttles up and
>> down continuously.  This is a tiring job after a while.  I used to
>> operate a Zodiac Hurricane 733 for the Canadian Coast Guard.  In calm
>> conditions, these boats are capable of fifty knots, but even offshore
>> with a sea running we can keep up a respectable 35 - 40.  For diving
>> application, it is important to keep all of the gear stowed as far aft
>> as possible, for the RIB to assume a proper trim in the water.  You
>> only need enough weight forward to make it possible to climb out of the
>> hole with engines trimmed full down - once on a plane, moving weight
>> aft will give a smoother (and dryer) ride as you trim up.  Higher speed
>> will actually give a more comfortable ride.  Like my RHIOT instructor
>> told me:  "drive it like you stole it".
>
>Hi Sean:
>
>Thinking about it, I have not had any experience with these larger sort of
>RIBs.  The boats that I've used around here have all been smaller RIBs with
>tiller control outboards that force you to sit in the back to operate.  This
>precludes the sort of agressive driving you are talking about and is
>probably why I think of them as being so wet.  So I'll defer to your obvious
>expertise on these larger boats.
>
>By the way, I just saw one of the local US Coast Guard boats getting hauled
>down the road on a trailer.  It appeared at first glance to be an RIB but on
>closer look the pontoons on the side were hard foam rather than inflatable
>air.  The boat was about 26 ft long and looked extremely tough.  It was
>powered by an outdrive rather than outboards and had a big center console
>with a big radar arch with searchlights and comm. gear.  I wish I knew what
>kind it was because it looked like a great boat for diving.  You happen to
>know the kind of boat I'm talking about?
>
>-Kent-

Understandable.  There is no way to keep sufficient control in a tiller
operated boat to properly manipulate the throttle while maintaining
your heading.

Yes, I think I know the one you are talking about, although I suspect
those tubes were inflatable and not foam.  Perhaps just severely
weathered?  I did the USCG cutter rescue swimmer course at a fleet
conference in Everett, and we used a RIB with outdrive as you
mentioned.  It was diesel powered.  The problem with these boats is the
large engine sitting quite a bit further forward than outboards - the
weight distribution made it difficult to bring the boat to proper trim.
 As well, you can not drop and return the RPMs as quickly as the
outboards - the net result being a rougher ride in the slop.  These
boats are tough though, and considerably less expensive to maintain. 
The outboards really take a beating when being used for SAR.  As I
recall, I never saw a set with over 300 hours on a Coast Guard boat.

I think Zodiac Hurricane has made RIBs specifically for diving, with a
large section of one of the tubes removable to facilitate getting a
diver on board.  These things tend to be quite expensive, though.  I
think your earlier recommendation of an aluminum skiff is definitely
the way to go, unless you honestly expect to be offshore frequently.

As an aside, the Canadian boats (Zodiac Hurricane 733) are 7.33 meters
long, with twin Mariner Offshore 150HP outboards using 5 bladed
stainless props.  Driver in center console atop batteries, after port
console with GPS and VHF atop tools and searchlights, after starboard
console with radar atops charts and spares.  Some of the newer ones
have electronic charts standard.  Cage supports radar, nav lights, GPS
and VHF antennae, as well as containing an inflatable self-righting
system and the tow bitt and drum with about 100 meters of polypropylene
line.  There is a small hatched compartment forward containing a fire
and salvage pump, air pump, and stuff like anchors, drogues and extra
line.  Oxygen kit, medical jump kit, spine board, basket stretcher with
flotation envelope, hypothermia treatment kit standard.  Yours for only
$110,000 to $125,000 CDN, depending on options.   ;-)

-Sean



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