Swell height. How big the waves are out in open water, before they hit the bottom and stand up. Where I surf, a 3-foot swell at a long period can make a head-high wave on the right sandbar, and a 3-foot swell at a short period can be knee-high mush. So height alone doesn't tell you much. Keep reading.

Period. The number of seconds between one wave and the next. This is the one most beginners ignore and it's the most important number on the report. Short period (8 to 10 seconds) usually means wind swell: choppy, close together, not much push. Long period (14 seconds and up) means the swell came from a storm far away, it's organized into clean lines, and each wave carries a lot more energy than its height suggests. A 3-foot swell at 17 seconds is a real day. A 5-foot swell at 8 seconds is a mess.

Direction. Where the swell is coming from. Our coast faces mostly west and southwest, so a northwest swell has to bend around points to get into some spots (which makes it smaller and cleaner there) and hits others straight on. South swells in the summer light up spots that are dead all winter. After a few months you learn which direction turns on which beach. That's local knowledge and it's worth more than any surf report.

Tide. The same spot can be perfect at low tide and a closeout at high, or the reverse. Beach breaks around here mostly like a low to medium incoming tide. Some of the reefs need a bit of water on them or you're surfing over rocks. Get a tide book from the surf shop (they're free) and keep it in the car.

Wind. Offshore wind (blowing from land out to sea) holds the wave face up and grooms it clean. Onshore wind (from the sea toward land) crumbles it. This is the whole reason for dawn patrol: in the morning the land is cool, the wind is usually light or offshore, and by 11 a.m. the sea breeze picks up and blows it all out. Glassy means no wind at all. Glassy is the best word in surfing.

Wetsuits are described by thickness in millimeters, body then arms and legs: a "4/3" is 4mm on the body and 3mm on the limbs. Thicker is warmer and stiffer. Here's what I wear:

• Fit matters more than brand. A wetsuit should feel too tight in the store. If water can slosh around inside it, it's not keeping you warm.
• Rinse it in fresh water after every session and hang it in the shade, inside out, on a wide hanger (not a wire one, it'll stretch the shoulders). Never leave it in a hot car.
• Dawn patrol trick: bring a big jug of hot tap water in the car and pour it down the suit before you put it on. Best two dollars you'll never spend.
• Booties: buy them a half size small. They stretch.
• A used 4/3 from the surf shop's rack is fine for your first season. Check the seams and the zipper.

1. Don't drop in. This is the big one. The surfer closest to the peak (where the wave first breaks) has the right of way. If somebody is already up and riding toward you, you do not take off in front of them. Ever. Pull back, let them go, and get the next one. Dropping in on someone is how fights start, and it's dangerous, because you'll both end up in the same place at the same time.
2. Paddle wide. When you paddle back out, don't paddle straight through the spot where people are riding. Go around, through the channel or the whitewater, even if it's more work. If you're in somebody's line, you're in their way, and it's on you to move.
3. Don't snake. Paddling around somebody to get closer to the peak and steal their priority is called snaking. Everybody sees it. Wait your turn. The lineup is a rotation and it works if you let it.
4. Respect the locals. If you're new at a spot, sit off to the side, take a few smaller waves, don't paddle straight to the peak and start hassling for sets. Watch who's getting the good ones and let them have them. Say good morning. Being friendly and patient goes about 90 percent of the way. The other 10 percent is having a sense of humor about it when some guy has a bad day.
5. Hang on to your board. Bailing your board and diving under a wave with nobody behind you is fine. Doing it with somebody paddling out behind you means they get hit by nine feet of fiberglass. Look first. Use a leash (nobody's too cool for a leash) but don't count on it.
6. Don't bring your whole crew. Six guys pulling up to a spot with two people out changes the whole vibe. Show up with a friend or two. Spread out.
7. If you mess up, say sorry. Everybody drops in by accident sometimes. Paddle over and apologize. It fixes almost everything.
8. Pick up your trash and somebody else's. Not a lineup rule, but a rule.

• 6'2" shortboard, three fins. Thin, narrow, a little rocker. For the good days with some push: Hollow Point on a west swell, Shelly's when it's overhead. Hard to paddle, quick to turn. It's the board I ride the least and love the most.
• 7'0" funboard. Sort of a fat shortboard, sort of a short longboard. Easy paddler, catches everything, still turns. This is the one I grab when the report says "2 to 3" and I don't know what I'm going to get. If you're a beginner buying your first real board, buy something like this, about a foot taller than you.
• 9'2" longboard, single fin. Heavy, old, dinged, and I'll never sell it. For the small glassy mornings when you just want to walk up and down a wave and not think about anything. Also for teaching. A longboard on a 2-foot day is more fun than a shortboard on a 4-foot day, and anybody who tells you different is trying to look cool.

1. Be a strong swimmer first. Not "I can swim." Strong. You'll be in cold water, tired, with a board yanking at your ankle, sometimes a long way from shore. If you can't swim a quarter mile in a pool without stopping, do that first.
2. Start on a big board and a small day. A long, wide, thick board (a foam softboard from a rental shop is perfect) on a 2-foot day at a sandy beach with no rocks. Not a shortboard. Not a 5-foot day. You'll catch ten times as many waves and learn ten times faster.
3. Start in the whitewater. Your first sessions, don't even paddle out. Stand in waist-deep water, turn the board toward shore, push off into the broken wave, and practice popping up. Once you can stand up on whitewater every time, then go outside.
4. Take a lesson, or get a patient friend. An hour with somebody who knows what they're doing saves you a month of flailing. (I've taught six cousins. It's a big family.)
5. Fall flat. When you wipe out, fall flat like a starfish, not feet first. The water is shallower than you think. Cover your head when you come up; the board is somewhere near you.
6. Go a lot. Once a month, you'll never get it. Three mornings a week, you'll be surfing by winter.
7. Nobody's watching. You think everyone on the beach is looking at you. They're not. They're looking at the waves.
8. Read the etiquette section above before you paddle out with other people. Seriously. It's the difference between being welcomed and being a problem.