Thinking about diving? Try it first.

1. Try it in a pool

Most dive shops offer a short try-dive. PADI calls it Discover Scuba Diving, and other training agencies have their own versions. You learn a few basic skills in water shallow enough to stand up in, then swim around with an instructor right next to you. It's a low-pressure way to find out whether you can clear your ears and whether you feel comfortable underwater.

• It's for ages 10 and up in the PADI version.
• It isn't a certification. You can only dive with a professional supervising you.
• If your try-dive includes an open water dive, the instructor may be able to count it toward a full course later. Ask before you book.

2. Answer the health questions honestly

Before any scuba program you'll fill in a short diver medical questionnaire. It was written by diving doctors working with DAN and the Undersea and Hyperbaric Medical Society. If you answer "no" to everything, you're set. A "yes" doesn't mean you can't dive; it means a doctor needs to sign off first. Do that before your trip, not at the dock.

See the questionnaire (PDF)

3. What learning to dive involves

The first full certification is usually called Open Water Diver. In the PADI version it has three parts:

• Knowledge: reading or online lessons with short quizzes. Many people do this at home before the pool.
• Pool sessions: practicing skills like clearing your mask and sharing air in calm, shallow water.
• Four open water dives: in a lake, quarry or the ocean, usually over two days.

You'll need to swim 200 meters (or 300 with mask, fins and snorkel) and float for 10 minutes, with no time limit on the swim. Once certified, you can dive with a buddy to about 60 feet (18 meters). Kids from 10 to 14 earn a junior version with extra limits.

4. Pick a place to learn

The well-known training agencies, such as PADI, SSI, NAUI, SDI and RAID, are all widely accepted around the world. The instructor and the shop matter more than the logo on the card. Questions worth asking:

• How many students per instructor in the pool and in open water?
• Where are the pool sessions and open water dives, and when?
• What's included in the price: online lessons, gear rental, open water dives, entry fees?
• Which gear do I need to buy? Most shops ask you to own a mask, snorkel, fins and boots.
• Do you run trips and fun dives after the course? A shop with an active dive club makes it much easier to keep diving.

Already certified?

See New to diving for tips on your first trips, gear and keeping your skills sharp. And start your logbook with the DiveFolk Logbook or our free dive log spreadsheet.