An Israeli amateur diver found a large, 900-year-old sword dating back to the Crusades at the bottom of Mediterranean Sea last week, Israeli researchers said on Monday.

The diver, identified as Shlomi Katzin from Atlit, Israel, discovered the weapon on Saturday among other artifacts on the Mediterranean seabed, including ancient stone anchors, other anchors made of metal, and pottery fragments, according to the Israel Antiquities Authority (IAA). The sword has a blade over 39 inches long and a hilt measuring nearly 12 inches, and it likely once belonged to a crusading knight.

Katzin brought the sword ashore after fearing it could be further buried under the sea’s shifting sands. He then reported his find to the IAA and was given a certificate of appreciation for “good citizenship,” an IAA spokesperson said.

“The sword, which has been preserved in perfect condition, is a beautiful and rare find and evidently belonged to a Crusader knight,” said Nir Distelfeld, inspector for the IAA’s robbery prevention unit. “It was found encrusted with marine organisms, but is apparently made of iron. It is exciting to encounter such a personal object, taking you 900 years back in time to a different era, with knights, armor and swords.”

The sword and the other items were found off Israel’s Carmel coast, which has many natural coves that provided shelter for ancient ships during storms, according to Kobi Sharvit, director of IAA’s marine archeology unit. Settlements and ancient port cities also developed around some of the larger coves, he said.

“These conditions have attracted merchant ships down the ages, leaving behind rich archaeological finds. The recently recovered sword is just one such find,” Sharvit added.

As for the anchors, Sharvit said some of them date back millenniums further than the sword.

“Identification of the various finds shows that the anchorage was used in as early as the Late Bronze Age, 4,000 years ago,” he said. “The recent discovery of the sword suggests that the natural cove was also used in the Crusader period, some 900 years ago.”

After the sword is cleaned and analyzed in the IAA’s lab, it will go on public display.