Bob Halstead is the pioneer of Papua New Guinea diving, and after diving and photographing the Coral Sea for more than 40 years, he knows a little something about the area. So his Coral Sea Fish Guide app, available on iTunes, is worth checking out.

With 2,000 color photos of more than 850 marine species (probably all of which Halstead has personally encountered), the guide is an easy way to identify and learn about reef fish, predators and critters in Papua New Guinea, the Great Barrier Reef, Solomon Islands, Vanuatu, New Caledonia and beyond. Whether you know what you're looking for, or need to place a name to the fish you've just seen, iPad and iPhone users can use images to quickly browse different species, or search for species under their "Common," "Scientific" or "Group" name.

In the "My Reef" section, you can log your own notes or create a list of favorite animals seen on a Coral Sea dive. For hard-to-identify creatures, there's a "Rogue's Gallery" of photos and info about unusual marine life.

If you haven't had a chance to dive with Halstead in PNG and get his expert take on diving and his salty Aussie view of the world, then Bob Halstead's Coral Sea Fish Guide is the next best thing, and you'll still have a rich source of information for your next dive trip in those environs. Download the app for $5 at https://itunes.apple.com/us/app/bob-halsteads-coralsea-fish/id809624974?ls=1&mt=8

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