: I'd like to hear about the brands you have and what you liked or did not like
: about them so I can project those characteristics onto the next generation.

I have a bunch of Sony Cybershot DSC p- cameras, and two waterproof
housings (as cameras get smaller, the old housings don't fit the newer
cameras). These have been very good.

We've had two Pentax optios. One was destroyed snorkelling in quite shallow
seawater when only a few weeks old. In general, immersion is a less harsh
environment than the deck of a kayak where a camera can heat up in the sun,
and then suddenly be immersed by a wave washing over the deck. That can
easily drop the internal pressure by 10-15% as the camera is cooled, which is
like a sudden immersion to 1-1.5m. I've killed two marine GPS units that way
and don't trust "waterproof" cameras unless they are serious ones intended
for diving. The Sony housings are good to 40m.

: How do you keep water and salt off the lens?

I took a plasterers squeegee and cut it into pieces with a bandsaw. Each
piece makes a good wiper for the front port of the housing. Lick or rinse
off sand first. Drying still leaves salt, so you may want to carry a
squirty bottle of fresh water.

: Personal tricks and tips for use?

Tie it on - they sink !!

: Any Mac compatibility problems?

Macs are basically Unix, so you get a command line. Use a card reader. You
can tail the log file which tells you where the computer has recognised the
card, and mount it where you want it, not where some software thinks you
ought to mount it... Vastly easier than trying to do anything with Windows.

Or you can put a little file on the memory card and have a script which
reads that to decide which camera it is from and copy files appropriately -
this is what I do when I can't afford the weight of a laptop and just take
a little network-attached hard drive (which runs Linux internally). As soon
as the card is plugged in, the device mounts it, reads the files, deletes
them off the camera and shuts down when finished. You can write a similar
script for a computer (presumably without the power-down as you'll want to
view them :-) which not only empties the camera but does the backups to
independent hard drives (always back valuable photos up at once to at least
three different machines in at least two different buildings to avoid the
risk of loss - you can do more permanent backups a bit more leisurely once
the initial redundancy is established).

Andy