Tim writes:

> I fly rc planes and heli's for a hobby too.

I gave that hobby up, but every summer, I get a yearning for an R/C sailboat

> seems from what ive read you need diff types of
> equipment for diff dive situations.

Yes and no.   Its pretty obvious that you're going to tailor your thermal
protection based on how cold/warm/hot the water is, but for a lot of the
other stuff, its generally not necessary.  For example, your mask isn't
going to change.  To break it down some:

Water temperature   --> Thermal protection (drysuit, wetsuit, no suit)
Thermal protection  --> weightbelt (thicker suit = heavier weightbelt)
weightbelt                --> minimum lift capacity of BC requirements

Extreme and/or Specialty environments:
   Ice diving     --> freezeproof regulator
   Deep diving    --> ultra high performance regulator
   Nitrox diving    --> O2-cleaned equipment (MAYBE.  It depends on %O2)

Putting this together, the typical recreational diver doesn't go out ice
diving, or does he go deeper than 130-150fsw.  As such, a nonspecialized
"middle-of-the road" regulator will be just fine.  If they add freshwater
ice diving (or very cold water), then they will benefit from a freezeproof
regulator.  This regulator will also be fine for warmer water recreational
diving, but because some methods of freezeproofing reduces regulator
performance, a freezeproof regulator probably not going to be good choice if
they also choose to take up deep (200-400fsw) technical diving, so more than
one regulator is probably going to be needed to cover both extremes, if that
diver is doing both (which is pretty rare).  FWIW, this is really more of an
issue on Piston 1st stages than on Diaphragm 1st stages.

Similarly, there's some requirements synergism with the BC sizing.
Generally speaking, the colder the water, the thicker the insulation, the
bigger the weightbelt and thus the more BC lift you're going to need.
Simplistically, you could just get the biggest, baddest BC you can find, but
big=drag, so you don't want it to be larger than it needs to be.   This is
why they have 'tropical' BC's with very low lift capability for people who
aren't diving up north.  These BC's are fine for when you're only diving in
a skin in warmwater, but they should not be used in coldwater.  OTOH, having
too big of a BC in warmwater is merely a drag penalty, so one coldwater
capable BC can meet both needs.

Let's see...mask & fins?  One mask that fits and one set of fins, although
if you're trying to dive in both cold and warmwater, you're going to bring
along your 1/4" booties with your fins, or choose to buy a warmwater pair
with a full foot pocket.

Diving without a wetsuit in warmwater with the coldwater ankle-high booties
looks funny so some people find a pair of warmwater fins to be more
dignified.  There is one legit concern with wearing coldwater booties
without a wetsuit and that is that  once they get old, the zippers can start
to slide down, which is a problem.  Either put some rubber bands around the
top, a Velcro wrap or buy a new pair :-).  However, I do find booties of
some sort to be very useful on shore dives in warmwater, so if high-top
coldwater booties aren't your thing, consider a pair of the low height
'slipper' booties.  These don't have zippers, don't look funny and save you
from the temptation of buying another set of fins.  Or get a thin warmwater
wetsuit and just tuck in your booties :-)

> are there any wreck dives under 100ft?? it sounds as if most of
> them are over 100ft and require special gases to do.

Many resorts will try to have a wreck or two around for recreational divers
to go poke around in.  I noticed that the website you mentioned has a trip
to Cayman Brac in March and I'm familiar with this destination (I'm planning
on heading down there again this fall):  there's three popular wrecks on
that island that are all shallower than 100fsw.  All (of these three) were
purposefully sunk.  They are as follows:

 - the Cayman Mariner (an old crewboat upright on the
   sand in 55fsw); see:

 - the MV Captain Keith Tibbets (Russian Destroyer #356, sunk
   in 1996; depth to sand at stern is 50fsw, 105fsw at bow); see:

 - the Kissamee (old tugboat sitting inverted in 40fsw water);
   sorry, I don't have any pic's of this one on my webpages.

FWIW, there's also one "genuine" wreck on the Brac, the Chester Polling
(sic), but its not in recognizable form and its not in a particularly easy
location to dive.