Hi Glen,
     I wish that my wife would have waited until the discount theatres
to see that particular movie.  Anyway, there has been research done
withj artificial gills since the early 50's or so.  There has been some
success with small rodents and the like but infection and rejection
phenomena are a considerable problem.  As for a man sized mammal there
is an additional consideration that heat loss and the oxygen requirement
for a warm blooded animal are proportionally much higher than an
equivelent cold blooded animal.  Thus the proportional increase in
surface area over that supplied by the normal lung surface area.
     There is a different tack being taken by some researchers that I
did some work with for a while though.  They are trying to make a unit
that extracts dissolved gasses from water that can then be tapped for
breathing in a normal fashion.  It would resemble the backback on a
space suit should the technology ever work out.
     Be wet and well.
Dennis
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