The Old Code Still Holds

Out at sea, clarity isn’t optional - it’s survival. For sailors, precision is as instinctive as reading wind shifts or plotting a course. Long before satellite radios and AIS systems, we communicated with what we had: flags. A square of fabric could signal distress, announce arrival, or warn of quarantine. These weren’t decorations - they were life-saving messages stitched into cloth.

But maritime flags have always been more than just tools. They’re tradition, etiquette, identity. And now, unexpectedly, they’re becoming something else: signals for change. Today, as navigators become more aware of the environmental footprint of their tools and gear, these symbols take on renewed significance.

The Old Code Still Holds

The International Code of Signals, first formalized in 1857, isn’t just history - it’s still in use. It assigns meaning to each of the 26 alphabet flags - critical for non-verbal communication between vessels.

• Flag “N” over “C”: “I am in distress and require immediate assistance.”
• Flag “L”: “You should stop your vessel instantly.”
• Flag “Q” (yellow): “My ship is healthy and I request free pratique.”

You’ll see them at regattas, shipyards, and on the backstay of a singlehander crossing the Atlantic. They’re analog, yes - but also universal, battery-free, and glitch-proof. Ensigns, burgees, club colors - they speak of allegiance and history, even before you hail on Channel 16. The sea has always run on symbols, and flags are among the most durable.

Durable, Yes. But at What Cost?

That durability, though, hides a cost. Most flags today are made from woven polyester. It lasts long, keeps color, flaps confidently in heavy weather. But when it finally breaks down - and it always does - it doesn’t disappear. It dissolves into microplastic.

According to the European Environment Agency, synthetic textiles contribute an estimated 16–35% of all microplastic pollution in oceans. In Europe alone, over 8% of marine microplastics come directly from textiles. Even in Antarctica, researchers have found polyester marker flags shedding up to 25% of their mass into pristine environments. The irony is stark: symbols meant to guide us leaving behind pollution we can’t see.

Hemp at Sea: Old Fiber, New Meaning

If you’ve ever stood at the helm in a stiff breeze, salt drying on your lips, you know what the elements can do to gear. Flags snap like gunshots. Sun bleaches colors. Rain and wind fray edges with the patience of time. That’s where most synthetic flags thrive—and die. They endure, sure, but when they’re spent, they linger. Not on your boat, but in the sea, broken into microplastics that drift through ecosystems for decades.

Sailors are often the first to witness environmental changes - rising sea levels, degraded coral reefs, trash floating mid-Atlantic. We navigate not just by GPS, but by instinct and memory, noticing when the water feels warmer, when the seabirds don’t show up

That’s where hemp reenters the story - not as novelty, but as return.

Before polyester, hemp sailed with us. Its fibers spun sails, rigging lines, and signal flags for generations. And it turns out, it still works. Exceptionally well, in fact. Hemp resists UV radiation better than cotton. It breathes, sheds mildew, and stays strong—even when wet. When its job is done, it decomposes without a trace. No slivers of polymer washing up on a distant shore.

Modern studies back this up. Hemp’s tensile strength far outpaces cotton and rivals synthetics. Its structure naturally resists microbes and mold. And unlike polyester, it won’t add to the 500,000 tonnes of textile microfibers entering our oceans every year.

Choosing hemp for flags isn’t a compromise - it’s a realignment. A way to let the signal mean what it says: we care about the sea, and we’re listening.

Polyester vs. Hemp: A Sea-Tested Comparison

Out at sea, gear that lasts isn’t a luxury - it’s a necessity. Polyester flags dominate the market for good reason: high tensile strength, colorfastness, and resistance to wind and UV. But when they finally fail, they fragment into microplastics - an estimated 16–35% of marine textile pollution, with polyester being a major culprit.

Hemp, by contrast, was history’s fabric - used for sails, rigging, flags for centuries. Modern tests reveal hemp’s advantages: toughness comparable to synthetics, resistance to mold and UV, breathability, and, crucially, full biodegradability without shedding microplastics. It offers performance without the environmental aftershocks.

When you weigh tens of thousands of tonnes of ocean microfibers per year against a material that returns cleanly to nature, polyester becomes a Faustian bargain - performance at a cost. Hemp isn't ideal in every respect - it may soften with time, and some fade may happen - but at sea, durability is defined in seasons, not decades. And if a hemp flag fails, it’s not another piece of plastic drowning in the environment. It’s just cloth returning to earth.

Proof in the Wind: SY Atmos and the EarthFlag

For sailors who take pride in keeping their bilges clean and decks shipshape, this raises a challenge: can we signal smarter? For coastal sailors, regatta organizers, or environmental NGOs, switching to sustainable flagging sends a message - literally and symbolically.

This isn’t theory - it’s happening now. Captain Willem Jan Landman, skipper of SY Atmos and chair of the Sail4Earth Foundation, isn’t waiting for regulations to catch up. His voyages span from the Baltic to the fjords of Norway, carrying more than crew and provisions: they carry meaning.

"With Atmos we are sailing long-distance voyages... For Sail4Earth, the Hemptex EarthFlag is our symbol of belonging," Landman says. "A Flag which unites us and through which we can tell the story of taking care of Planet Earth. As an architect and a sailor I know integrity is in the details. For years, people flew flags for sustainability that were made of polluting plastic. The message and the medium were completely disconnected."

As of September 2025, Landman and a flotilla of yachts are setting sail for Belém, Brazil, to attend COP30. Every vessel will fly a custom Hemptex EarthFlag - turning every mast into a masthead of climate action.

A Cultural Shift Underway

A hemp courtesy flag might not last 10 seasons - but maybe it shouldn’t. Maybe that impermanence is the point: use it, honor it, return it to the sea without harm.

These aren’t fringe ideas. They’re the beginnings of a cultural shift within maritime tradition: one that respects the old codes but updates the materials.

A widespread move away from synthetic flags is still a future scenario. But one that may happen faster than expected by many. Frontrunners like this hint at how tradition and environmental values may eventually converge. This isn’t nostalgia - it’s innovation anchored in tradition. Flags that once told others who you were are now telling them what you stand for.

Maybe a hemp flag won’t last ten seasons. Maybe it shouldn’t. Maybe that impermanence is the point. Use it. Honor it. Let it return to the sea without harm.

Portugal, for example, now hosts over 430 Blue Flag-certified beaches and marinas - each required to meet stringent sustainability and environmental education criteria. The Netherlands, similarly, boasts more than 140 Blue Flag marinas. While none of these have transitioned to hemp flags yet, these certifications reflect a broader commitment to sustainability - and signal potential openness to further innovations in eco-conscious materials.

Mini FAQ — From the Mast Down

How long will a hemp flag last in marine conditions? Expect several seasons under normal use. Hemp is UV-resistant, mildew-resistant, and strong - though long-term marine trials are ongoing.

Does hemp mold or mildew in humid climates? No more than any other natural fiber—and often less. Its natural antimicrobial properties reduce mildew risk.

Can hemp flags bleed or shrink? Hemptex flags are printed with water based pigment inks. These inks have one of the highest UV-vastness scores of any textile tested and 9/10 score for robustness. The dying process does not take any water outside of the inks themselves. No washing is needed before or after the printing, which preserves massive quantities of water. However, exposure to saltwater, intense sun, and frequent wet-dry cycles may cause some natural fading over time - especially with darker dyes. Shrinkage is minimal if the flag is pre-shrunk and air-dried. Washing is rarely needed, but if done, rinse gently with fresh water and let air-dry flat. Avoid dryers and high heat.

Does cleaning hemp damage the fibers? Not when cared for properly. Hemp is even stronger when wet and becomes softer over time - unlike polyester, which can embrittle with repeated UV and heat exposure.

Course Correction

To sailors, flags are more than decoration - they’re navigational tools, tokens of tradition, and expressions of respect. But as guardians of the ocean, we’re also stewards. The tools we use - ropes, sails, banners - should reflect the values we carry onboard. Choosing the right material isn’t about aesthetics; it’s about coherence. When a hemp flag waves from a mast, it isn’t just a signal - it’s a statement: we respect the sea that sustains us.

‍