What was this bottle used for? Guantanamo Bay, Cuba

by Patty Butler

Aqua green color piece of glass with STRAD (may be partial word) and FLUID embossed on the glass that is approximately 1x1/2 inches and found in Guantanamo Bay, Cuba while I was snorkeling.

Beachcombing at Guantánamo Bay, Cuba

🌊 Glass Beach – A Sea Glass Treasure Trove

Glass Beach at Guantánamo Bay lives up to its name spectacularly. The beach is “littered with sea glass, much of it jewelry quality,” and divers report that the ocean floor is layered in glass, shining in the sunlight.

Sea Glass Colors & Rarity

• Common hues: aqua, green, brown, white, and many variations.


• Rare finds: large cobalt blue, black, red, and even orange or yellow.


• Black glass may date back to 19th-century bottles from shipwrecks or military disposal.

Collecting Experience

Beachcombing here is rated “Excellent”, with up to 16+ jewelry-grade pieces found per hour. Much of the glass is well-worn and ideal for collectors or craftwork.

Where to Go & What to Bring

Top Spots

• Glass Beach: The most concentrated sea glass area.


• Girl Scout Beach: Slightly less glass, but still good hunting.

Timing & Technique

• Visit after storms or high tides for
  the best chance of new discoveries.


• Search both the shoreline and shallow water zones.


• Bring mesh bags, gloves, and possibly a snorkel for underwater finds.

The Story Behind the Glass

Guantánamo’s glass likely originates from decades of naval activity. Some bottles may be linked to places like the old “White Hat Club,” where sailors discarded bottles directly into the bay. Others may stem from older shipwrecks. These origins lend historical intrigue to each piece.

Logistics & Visitor Notes

• Base Access: Glass Beach is on the U.S. Naval Base and is not open to the general public without clearance.


• Export rules: Sea glass is typically considered debris and can be taken legally, but confirm with base guidelines.


• Visitors report collecting large amounts, sometimes over 25 pounds per trip.

Tips for a Successful Visit

• Plan visits at low tide or early morning.


• Focus on wrack lines and rocky areas for hidden treasures.


• Use padded pouches to transport delicate finds safely.

Why It’s Unique

Guantánamo Bay offers one of the richest sea glass experiences in the world:

• High density of jewelry-grade glass


• Rare colors like red, black, and cobalt blue


• Strong historical connection to naval and maritime activity

Final Thoughts

If you can access the base, beachcombing Glass Beach at Guantánamo Bay is a dream for collectors and history lovers. It’s one of the most unique and rewarding sea glass destinations on Earth.

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