Submerged obstruction
Something on or near the seabed that could damage a ship, an anchor or fishing gear — its nature often unknown.
"SUBMERGED OBSTRUCTION VICINITY 49-40.8N 003-43.8W. WIDE BERTH REQUESTED." An obstruction can be anything from lost fishing gear to a piece of wreckage or a lost anchor. Often nobody knows yet: a survey found a contact, or a trawler snagged something.
Obstruction warnings tend to be reissued unchanged for months while the contact is investigated, then cancelled once it is charted or removed.
What the archive shows
221 messages in this archive use “Submerged obstruction”, the earliest issued 1988-06-07 and the latest 2026-06-03. 1 of them is in force in the latest lists we collected. A hazard reported again and again counts once per message.
The largest yearly count is 2014, with 16 messages. Collection is incomplete between 2024-05 and 2026-08-17, so 2024, 2025 and 2026 are not comparable with fully collected years.
Wrecks accounts for 197 of 221 recorded messages (89%), the largest warning type group in this selection.
Located messages that use it fall in 38 sea areas; the most frequent are North Sea (29), Persian Gulf (25) and English Channel (21).
Messages that use it are issued most often in June (28 across all years) and least often in April (9).
By warning series: HYDROLANT 93, HYDROPAC 83, NAVAREA IV 26 and HYDROARC 11, and 2 more.
Messages using it, by year of issue
By month of issue, all years
Where it appears · 38 sea areas
In force now · 1
- NAVAREA IV 525/26 · Wrecks · North Atlantic Ocean2026-06-02 · in force
NORTH ATLANTIC. BAHAMAS. 1. OBSTRUCTION, 20 METERS BELOW SURFACE, IN 24-50.93N 077-48.83W UNTIL 30 NOV 2. CANCEL THIS MSG…
Obstruction, 20 meters below surface, in 24-50.93N 077-48.83W until 30 nov 2. cancel this msg 010001Z dec 26 →
How it reads in recent messages
- HYDROPAC 2677/25 · Wrecks · Persian Gulf2025-10-19
PERSIAN GULF. U.A.E. DNC 10. OBSTRUCTION REPORTED IN 25-19.55N 055-14.79E.
Obstruction reported in 25-19.55N 055-14.79E → - HYDROLANT 1143/24 · Wrecks · Bay of Biscay2024-05-28
BAY OF BISCAY. FRANCE. DNC 08. SUBMERGED OBSTRUCTION MARKED BY YELLOW BUOYS IN 45-39.63N 001-40.58W.
Submerged obstruction marked by yellow buoys in 45-39.63N 001-40.58W → - HYDROPAC 1550/24 · Wrecks · South Pacific Ocean2024-05-09
PERU. DNC 07. SUBMERGED OBSTRUCTION REPORTED, WRECK, F/V DON GUILLERMO IV SUNK IN 05-04.65S 081-05.08W.
Submerged obstruction reported, wreck, F/V don guillermo IV sunk in 05-04.65S 081-05.08W → - HYDROPAC 958/24 · Wrecks · South Pacific Ocean2024-03-22
PERU. DNC 07. SUBMERGED OBSTRUCTION REPORTED, WRECK, F/V SANTISIMA CRUZ SUNK IN 16-24.30S 073-13.00W.
Submerged obstruction reported, wreck, F/V santisima cruz sunk in 16-24.30S 073-13.00W → - HYDROPAC 231/24 · Wrecks · Great Australian Bight2024-01-19
GREAT AUSTRALIAN BIGHT. AUSTRALIA. DNC 05. OBSTRUCTION REPORTED, 45 METER PONTOON ANCHORED IN 35-16.16S 137-04.95E. ONE MILE BERTH REQUESTED.
Obstruction reported, 45 meter pontoon anchored in 35-16.16S 137-04.95E → - HYDROPAC 194/24 · Wrecks · Great Australian Bight2024-01-16
GREAT AUSTRALIAN BIGHT. AUSTRALIA. DNC 05. 1. OBSTRUCTION REPORTED, 45 METER PONTOON ANCHORED IN 34-46.54S 136-33.07E. ONE MILE BERTH REQUESTED.…
Obstruction reported, 45 meter pontoon anchored in 34-46.54S 136-33.07E → - HYDROPAC 3499/23 · Wrecks · Persian Gulf2023-11-06
PERSIAN GULF. QATAR. DNC 10. 1. OBSTRUCTIONS REPORTED IN VICINITY: A. 25-58.42N 051-35.40E. B. 26-10.67N 051-53.03E. 500 METER BERTH…
Obstructions reported in vicinity: a. 25-58.42N 051-35.40E →
Earliest in the archive
- NOAAORR-6580 · Spills · The Coastal Waters of Southeast Alaska and British Columbia1988-06-07
…of a reddish colored slick, which appeared to be hydraulic fluid, in the vicinity of Obstruction Pass between Orcas and Sucia Islands. USCG district 13. 2. COMMODITY: HYDRAULIC FLUID.…
Mystery Spill6; orcas island, washington →
Often in the same message
Related terms
- Dangerous wreck
- A sunken vessel close enough to the surface to endanger ships, or wreckage reported in the water.
- Wide berth requested
- Keep well clear — or, when a distance is given ("TWO MILE BERTH REQUESTED"), at least that far away.
- Shoal / reported depth
- Water shallower than the chart shows — a newly found shoal, a reported depth, or less water than charted.
Warning types that use it
- Wrecks — Dangerous wrecks, shoals and submerged obstructions.
Counts cover the messages in this archive that use the term, recounted 2026-09-24; see coverage for what is collected and since when. Not for navigation — follow official NAVAREA and coastal broadcasts.