In the unforgettable “Pirates of the Caribbean” films, the buccaneers were guided by a code of conduct that was originally created by the Brethren Court of pirate lords. Theoretically, its rules were strict and unbending — but before the end of the first film, heroine Elizabeth Swann convinced the crew of the pirate vessel Black Pearl that “they’re more like guidelines, anyway.”

Florida Keys sea turtle Pennekamp

The Keys’ underwater wonders are particularly spectacular along the coral reef tract near Key Largo’s John Pennekamp Coral Reef State Park — America’s first undersea preserve. (Photo by Frazier Nivens, Florida Keys News Bureau)

Though buccaneers are few and far between in the Florida Keys (sometimes called the American Caribbean), Keys residents and others who love the island chain are definitely guided by a code of conduct.

This code was designed to protect a treasure richer than any pirate gold — the region’s amazing natural environment. The Florida Keys are paralleled by the continental United States’ only living coral barrier reef, which is also the third largest in the world. Much like a tropical rainforest, the reef ecosystem supports an incredibly diverse population of plants and animals.

In fact, the entire land mass of the Keys is surrounded by the Florida Keys National Marine Sanctuary, which was established in 1990 by the U.S. government. Visitors will also find land-based refuges where birds, wildlife and their habitat are protected — including the Lower Keys’ National Key Deer Refuge that’s home to shy, soft-eyed miniature deer the size of large dogs.

So what exactly IS the Keys code?

Its core is the 10 Keymandments. Unlike the Bible’s 10 Commandments, which advise people what NOT to do, the Keymandments advise travelers what they CAN do to have a meaningful, memorable vacation while respecting and helping preserve the Keys environment.

Key Deer Lower Keys

A Key deer searches for food in the National Key Deer Refuge on Big Pine Key. About the size of a large dog, the deer are indigenous to the Lower Florida Keys. (Photo by Andy Newman, Florida Keys News Bureau)

Lighthearted yet educational, they’re guidelines for enjoying a sustainable travel experience in the laid-back subtropical spot.

ONE: Plant a coral (or adopt one of the cute little things, but don’t touch them on the reef).

TWO: Support the wildlife (volunteer food, funds or time to a local wild bird center).

THREE: Take out the trash (especially if it’s floating in the water).

FOUR: Capture a lionfish (any time and any size — we can show you how).

FIVE: Leave a digital footprint (share pictures with fans, friends and followers).

SIX: Hike it, bike it or hoof it (it’s low on eco-impact and high on fresh tropical air).

SEVEN: Catch dinner (and release all the fish you know you can’t eat).

EIGHT: Use a mooring buoy at dive sites (save your back and leave the anchor alone).

Crane Point Florida Keys trail

Crane Point Hammock, a unique Middle Keys site, feaures trees and plants found nowhere else in the United States. (Photo courtesy of Crane Point Hammock Museum & Nature Center)

NINE: Conserve vs. consume (reduce, reuse and recycle even on vacation).

TEN: Get off the beaten path (you can hike, bike, walk, kayak or paddleboard along Keys trails).

While the code of conduct in the “Pirates” films proved to be somewhat elastic, the Keys code should be followed at all times by everyone who cares about the area’s environment.

In fact, the Keymandments are a modern-day addition to more than a century of efforts to preserve it.

You can discover the island chain’s natural world with a knowledgeable local eco-tour guide or watersports operator — whether on a kayaking paddle through tranquil waters and surreal mangrove tangles, an excursion to view playful dolphins in the wild, or a dive or snorkeling trip in America’s first underwater park.

To whet your appetite for eco-adventures in the Keys, just click here. And don’t forget … to protect and preserve the Keys’ environmental treasures, matey, always follow the code.