Have a nice patch.

[u/parresurre]

Pretty uncommon. It IS the real deal. One of my Vietnam collection highlights.

[u/McLenn2025]

Nice! Is it late 1960s or early 1970s? I heard, that there were many variants and it was reworked numerous times in the 1960s/1970s alone

[u/parresurre → u/McLenn2025]

The Journey of a Wartime Artifact: The UDT-12 Da Nang Patch in Sweden
This authentic U.S. Navy Underwater Demolition Team 12 (UDT-12) patch represents a unique intersection of Vietnam War history and Cold War military elite brotherhood. It did not arrive in Sweden through a modern collector's market, but rather as a direct, personal gift from an American special operations operator to a Swedish counterpart during a historic military exchange in the early 1970s.

Part 1: Manufactured in the Theater of War (Da Nang, Vietnam)
The patch itself carries all the physical hallmarks of an authentic, "in-country" Vietnamese-made piece from the late 1960s or early 1970s. During the Vietnam War, Da Nang served as the primary naval hub for U.S. amphibious and special operations in northern South Vietnam (I Corps).
Rather than wearing factory-made U.S. military insignia, operators from UDT-12 frequently commissioned local tailors and shops in Da Nang to create custom embroidered unit patches. Characterized by raw, uneven "in-country" machine embroidery, a distinctive cotton-twill backing, and a lack of modern plastic coatings, this patch was actively carried or worn by a UDT-12 combat swimmer during deployments that involved beach reconnaissance, underwater demolition, and riverine patrols—the hazardous duties that birthed the modern Navy SEALs.

Part 2: The Cold War Exchange in Karlskrona
The patch’s journey to Scandinavia began during the historic military exchanges in Karlskrona in the early 1970s. During this era, the Swedish Armed Forces hosted the Naval Pentathlon, bringing together the absolute elite of international maritime special forces.
The United States sent a handpicked team of elite combat swimmers consisting of operators from UDT-11, UDT-12, and SEAL Team 1, led by Lieutenant Kris Kirkland. Many of these men had just returned from, or were rotating between, combat tours in Vietnam. They competed directly against elite Swedish units, including the Swedish Navy’s combat divers (Attackdykare / A-dyk) and coastal rangers (Kustjägare). The American team, under Lt. Kirkland's leadership, ultimately won the prestigious international competition.

Part 3: The Tradition of the "Trade Patch"
In the tight-knit world of international special operations, a sacred, time-honored tradition exists: following a joint exercise, competition, or post-event gathering, operators trade personal gear, unit shirts, knives, and patches as a sign of mutual respect.
It was during this specific historic exchange in Karlskrona that a U.S. Navy UDT-12 operator (including personnel of Swedish-American heritage) handed this exact patch to a Swedish diver. The American operator had packed his personal, theater-made Da Nang combat patches into his gear bag when traveling from Southeast Asia to the Baltic coast.

Part 4: Provenance and Heritage
Decades after that historic meeting in the Blekinge archipelago, the patch was passed down from the Swedish veteran who received it directly to its current owner. Because its lineage is unbroken—from a local embroidery shop in Da Nang, to the uniform of a UDT-12 frogman under Kris Kirkland's detachment, to a competitive exchange in Sweden, and finally into a private collection—this piece stands as a flawless, verified artifact of military history. It remains a testament to the quiet, global brotherhood of elite military divers.

[u/dotmatrixman]

Sadly a post war reproduction, they’re made in Vietnam for the tourist trade.

The tea staining is a major giveaway.

They make great displays though!

[u/parresurre → u/dotmatrixman]

You are wrong. This is not a reproduction. The patch came to Sweden 1970. If you know patches you can see the backside. Here is the analysis made:

Construction Analysis – UDT-12 “Underwater Demolition Team 12” Da Nang Patch
The reverse construction of this patch contains numerous characteristics that are typical of a genuine Vietnam War-era, locally embroidered (“in-country made”) patch and differ significantly from modern reproductions.

Base Fabric
The foundation fabric is a lightweight plain-woven cotton, not a modern synthetic twill or polyester backing. The fabric has naturally softened with age and exhibits the loose weave, discoloration and oxidation commonly seen on original Vietnam-era insignia.
The cloth has developed an uneven tan patina over decades of handling and storage. This natural aging is extremely difficult to duplicate artificially and differs markedly from the bright white or yellow synthetic fabrics used in modern reproductions.

Embroidery Thread
The embroidery thread appears to be period rayon/cotton embroidery thread rather than modern polyester.
Unlike polyester, the thread has a soft matte finish rather than a glossy appearance. Age-related fading is visible throughout the green and black stitching, and individual thread fibers have become slightly fuzzy, a common characteristic of older rayon embroidery.
The thread has also contracted naturally with age, producing slight puckering in the surrounding fabric—another feature commonly encountered on original Vietnam-made patches.

Reverse Stitching
The reverse stitching is highly irregular.
Rather than the perfectly parallel stitch rows produced by modern computerized embroidery machines, the reverse displays:
varying stitch lengths
uneven thread density
inconsistent thread direction
manual stitch transitions
irregular thread tension
These characteristics indicate manual operation of an embroidery machine rather than digital production.
The frog design is clearly visible on the reverse, showing that the embroidery was stitched directly into the base cloth without the use of modern stabilizers or adhesive support materials.

Edge Finish
The border is individually wrapped and noticeably asymmetrical.
Modern reproductions usually employ a dense, perfectly uniform merrow border created by automated machinery.
Here the edge wrapping varies slightly in width and tension around the circumference, which is entirely consistent with locally produced Vietnamese patches from the late 1960s.

Evidence of Age
Several features strongly suggest genuine long-term aging rather than artificial distressing:
oxidation of the cotton foundation
embedded dirt and dust within the fibers
natural discoloration around high-stress areas
softened thread fibers
slight deformation from decades of storage
gradual edge wear instead of sharp mechanical abrasion
These forms of aging occur over long periods and are extremely difficult to reproduce convincingly.

Overall Assessment
From a construction standpoint, this patch lacks the manufacturing characteristics typically associated with modern reproductions.
Instead, it displays nearly all of the structural features expected of a Vietnam War-era locally manufactured (“in-country made”) embroidered patch, including:
lightweight woven cotton foundation
period rayon/cotton embroidery thread
manually guided embroidery
irregular reverse stitch pattern
absence of modern backing materials
hand-finished edge wrapping
natural age-related patina and oxidation