Case file · Anomaly hotspot
Columbus in the Sargasso weed
From 16 September 1492 Columbus's ships sailed for days through mats of floating Sargassum weed, and his crews feared shallows or being trapped; the logbook records the weed and the sailors' anxiety.
1492 CE · 28.00, -40.00 · status: official
The account
This was the first written description of the Sargasso Sea. The fear that ships could be held fast by weed later grew into the legend of a 'sea of lost ships'. Position approximate.
The researched reading
An accurate early description of real floating seaweed. The legend of ships trapped in the weed came later and has no basis.
| Explanation | Weight | Why |
|---|---|---|
| Undetermined | 46% | The share a generic explanation had beyond what has been shown for this case: it fits many cases like this one, but has not been demonstrated for this one. |
| A known natural phenomenon | 40% | Columbus’s log describes the floating mats of Sargassum that collect in the North Atlantic gyre; the weed is free-floating and cannot trap a ship, and the crew’s fear of shallows was a natural reaction to a sight no European sailor had recorded. |
| Perception, memory or mind | 7% | Weeks out of sight of land, anxious crews read the weed as a sign of danger; the later "sea of lost ships" legend grew from such fears. |
| Something known, misidentified | 3% | Sailors briefly took the weed as a sign of nearby land, which was wrong. |
| A hoax or fabrication | 2% | The surviving log is Las Casas’s abstract, but the weed is described accurately. |
| A poorly understood natural phenomenon | 1% | Nothing here is poorly understood. |
| Genuinely anomalous | 1% | Nothing anomalous was reported. |
| Secret human technology | 0% | Not applicable to a 1492 voyage. |
Official position: No investigation needed; the observation is accepted as the first written description of the Sargasso Sea.