In 1968, Pete Sudnow took one step too many in defense of his nation. An Army medic in Vietnam, he strode onto an enemy land mine and it shredded his leg. It took 201 stitches and 26 pints of blood to put him back together after doctors extracted 2 1/2 pounds of shrapnel.

Sudnow returned home to Miami with two Purple Hearts, a 70 per cent disability and a sense of despair.

He worked for the Vietnam Veterans Against the War and was a coordinator for the rallies against the political party conventions in 1972. He didn't come to Washington for the big rallies in 1971 and he didn't throw his Purple Hearts on the Capitol steps. "I would have if I'd been there. The Purple Heart means nothing to me. That and 10 cents will get you a cup of coffee, if you can find cup of coffee for a dime."

Now that the war and the war against the war are over, Pete Sudnow's railroad is back on a track that leads him straight to Paradise every day.

He's the mate on the Sandpiper, a mahogany deep-water charter boat that works the green and deep blue seas around this low-keyed seaside city. It's all he ever wanted.

Slat-thin, with a hawklike nose and eyes that are piercing even through wrap-around sunglasses, he'll tell you, "I love my job. There's not many men that can say that,"

You think he's putting you on. How much, fun can it be - getting up at dawn every day, baiting other people's hooks, cleaning fish, unsnarling clumsy amateur's lines, talking to boring people about the weather, taking orders from the captain?

"No, I mean it. I love every bit of it. I'm down for seven days a week, all year.I'm here every morning at 7 whether we've got a charter or not. If we don't go out I work on the boat."

What about ambition?

"Oh, I want my own boat. I've already got my name down for a slip here, but there's a waiting list of about six years. I'll probably be 35 before I get one," he said.

Pete Sudnow isn't kidding. He's found his own Elysium and he's clinging to it like barnacles to a dock pilling.

Who could blame him? The Sandpiper cruises the emerald green sea daily over the great reef that lies off the Keys, then hurtles out into the clear blue sea-within-a-sea, the Gulf Stream, where dolphins, wahoo, tuna, marlin, sailfish and bonito frolic.

Sudnow gets to challenge that mighty sea from the fighting chairs aboard the Sandpiper, and in his spare time he takes his diving tank out to the great reef and lives with it.

Key West is exciting because the fishing is varied. On the Gulf side of the island, shall-draft skiffs work the crystal-clear flats after bonefish and barracuda. From the bridges that connect the keys you can snap up a bushel full of snapper and bottom fish. On the reef a big cuda, kingfish, group, mackerel, and bigger snapper and the might gamefish are always lurking out in Gulf Stream.

On Sunday we hit our good luck streak early, Art Moore, from Brooklyn, his ebullient Ecuadorian friend Inez Duffy and I shared a charter. Capt. Bob Hare worked the reef first and that's where the fish were.

The first hit was a spectacular kingfish, kin to the narrow mackerel but larger, that leaped a full foot to snatch our ballyhoo - an eight-inch baitfish that skips along the surface on a trolled line.

The king was woefully outmatched against our heavy gamefish rigs - stiff, six-foot rods, huge Penn Senator reels that could double as anchor winches, and 40-pound test monofilament with steel leaders.

In fact, that's the way it was with just about everything we landed - overmatched, except perhaps the 30 pound 'cuda Moore battled for 10 minutes before boating. But we were ready for anything and praying for sailfish.

"Oh, now that's a fish," said Sudnow. "He'll fight you all the way to the boat. They may leap 25 or 30 times before you get 'em in, and you've got to have that line dead taut all the time, because every time they jump, they're trying to spit the hook."

Even the boat is a monster job. "Get 'em up alongside and they want nothing but out. You can't gaff them. I just grab him by the bilL, one hand at the tip and the other as far in his mouth as I can get it. Then I hoist him in and Bob (Capt. Hare) comes down from the bridge and bops him over the head. You've got to. Those bills are dangerous."

Well, we didn't get us a sail, but someday we will. We did corral that big 'cuda, along with about 10 of his kin, plus two grouper, one upwards of 15 pounds, a couple of kings and some smaller mackerel. The one that got away was on Inez' line, a gorgeous five-foot kingfish that leaped spectacularly, stole the ballyhoo and sprinted off before she had the rod set.

And I had a half that got away. A nice 12-pound mackerel that got snapped in two by a big, greed 'cuda not 12 feet from the gaff hook. I got the front half.

I had to look twice at that poor, sorry half a mackerel when Sudnow dumped it in the catch bin. I had to think twice about Sudnow, a man who'd been close to that himself, who by sheer spunk and good nature had drawn himself back. A man who had managed, in the words of one of the Greeks, to learn to ply a simple trade and be content therewith.