Shoal / reported depth
Also written: less water than charted
Water shallower than the chart shows — a newly found shoal, a reported depth, or less water than charted.
"8.2 METER SHOAL REPORTED IN …" means a ship or survey measured less water than the chart shows. Sandbanks move, volcanoes and landslides change the seabed, and many charts still rest on surveys from the nineteenth century. Until the chart is corrected, the warning is the only notice of the danger.
Reported depths are only as reliable as the measurement behind them; warnings often say who reported the depth, or that it is unconfirmed.
What the archive shows
499 messages in this archive use “Shoal / reported depth”, the earliest issued 1976-12-15 and the latest 2026-09-18. 9 of them are in force in the latest lists we collected. A hazard reported again and again counts once per message.
The largest yearly count is 2017, with 32 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 419 of 499 recorded messages (84%), the largest warning type group in this selection.
Located messages that use it fall in 52 sea areas; the most frequent are North Atlantic Ocean (50), The Northwestern Passages (45) and North Sea (41).
Messages that use it are issued most often in September (76 across all years) and least often in June (27).
By warning series: HYDROLANT 157, HYDROPAC 147, HYDROARC 69 and NOAAORR 57, and 2 more.
Messages using it, by year of issue
By month of issue, all years
Where it appears · 52 sea areas
In force now · 9
- HYDROARC 242/26 · Wrecks · The Northwestern Passages2026-09-18 · in force
AMUNDSEN GULF. CANADA. 1. 0.3 METER ROCK DEPTH REPORTED IN 70-32.05N 115-59.06W. 2. DANGEROUS SUBMERGED ROCK REPORTED IN 70-30.05N 116-04.70W.
0.3 meter rock depth reported in 70-32.05N 115-59.06W → - HYDROPAC 1892/26 · Wrecks · Arabian Sea2026-07-01 · in force
ARABIAN SEA. INDIA. 6.2 METER DEPTHS REPORTED IN VICINITY: A. 18-17.72N 072-55.18E. B. 18-17.77N 072-55.92E.
6.2 meter depths reported in vicinity: a. 18-17.72N 072-55.18E → - HYDROPAC 473/26 · Wrecks · Persian Gulf2026-02-16 · in force
U.A.E. DNC 10. 12.9 METER DEPTHS REPORTED IN BOROUGE CHANNEL 24-09.00N 052-45.20E.
12.9 meter depths reported in borouge channel 24-09.00N 052-45.20E → - HYDROARC 178/25 · Wrecks · The Northwestern Passages2025-10-01 · in force
FRANKLIN STRAIT. MCCLINTOCK CHANNEL. CANADA. DNC 28. DEPTHS REPORTED: A. 29.3 METERS IN 71-22.82N 096-41.27W. B. 26.6 METERS IN 71-22.05N 096-40.73W. C. 11.3…
Depths reported: a. 29.3 meters in 71-22.82N 096-41.27W → - HYDROARC 175/25 · Wrecks · The Northwestern Passages2025-09-29 · in force
MCCLINTOCK CHANNEL. CANADA. DNC 28. 33.6 METER DEPTH REPORTED IN 76-40.36N 102-16.62W.
33.6 meter depth reported in 76-40.36N 102-16.62W → - HYDROARC 148/25 · Wrecks · The Northwestern Passages2025-08-31 · in force
LANCASTER SOUND. CANADA. DNC 28. 13.6 METER DEPTH REPORTED IN 74-38.63N 091-20.54W.
13.6 meter depth reported in 74-38.63N 091-20.54W →
How it reads in recent messages
- HYDROARC 204/26 · Wrecks · Kara Sea2026-09-02
KARA SEA. RUSSIA. 9.8 METER DEPTH REPORTED IN IN 68-35.51N 073-54.19E.
9.8 meter depth reported in in 68-35.51N 073-54.19E → - HYDROARC 202/26 · Wrecks · Davis Strait2026-09-02
DAVIS STRAIT. CANADA. SHOALS REPORTED IN: A. 68-16.14N 066-01.06W. B. 68-15.59N 066-01.09W. C. 68-15.29N 066-01.13W.…
Shoals reported in: a. 68-16.14N 066-01.06W → - HYDROARC 195/26 · Wrecks · Kara Sea2026-08-31
KARA SEA. RUSSIA. DEPTHS REPORTED: A. 14.3 METERS IN 70-14.06N 082-44.52E. B. 13.9 METERS IN 70-13.60N 082-44.59E. C. 14.6…
Depths reported: a. 14.3 meters in 70-14.06N 082-44.52E → - HYDROARC 189/26 · Wrecks · Kara Sea2026-08-26
KARA SEA. RUSSIA. DEPTHS REPORTED: A. 8.0 METERS IN 70-35.47N 083-27.80E. B. 9.6 METERS IN 70-35.35N 083-27.69E. C. 10.2…
Depths reported: a. 8.0 meters in 70-35.47N 083-27.80E → - HYDROARC 188/26 · Wrecks · Kara Sea2026-08-26
KARA SEA. RUSSIA. DEPTHS REPORTED: A. 10.4 METERS 70-40.17N 083-28.91E. B. 9.3 METERS 70-39.02N 083-28.73E. C. 7.5 METERS…
Depths reported: a. 10.4 meters 70-40.17N 083-28.91E → - HYDROARC 187/26 · Wrecks · Kara Sea2026-08-26
KARA SEA. RUSSIA. 1. DEPTHS REPORTED: A. 12.3 METERS IN 71-53.99N 082-35.35E. B. 9.7 METERS IN 71-53.34N 082-36.04E. C. 11.6…
Depths reported: a. 12.3 meters in 71-53.99N 082-35.35E → - HYDROARC 180/26 · Wrecks · Kara Sea2026-08-21
KARA SEA. RUSSIA. DEPTHS REPORTED IN: A. 5.5 METERS IN 73-02.72N 080-34.31E. B. 5.7 METERS IN 73-02.48N 080-33.76E.
Depths reported in: a. 5.5 meters in 73-02.72N 080-34.31E →
Earliest in the archive
- NOAAORR-6231 · Spills · North Atlantic Ocean1976-12-15
…15, 1976, the Liberian tanker Argo Merchant went aground on Fishing Rip (Nantucket Shoals), 29 nautical miles southeast of Nantucket Island, Massachusetts in high winds and ten…
Argo merchant; 29 miles southeast of nantucket island, massachusetts →
Often in the same message
Related terms
- Submerged obstruction
- Something on or near the seabed that could damage a ship, an anchor or fishing gear — its nature often unknown.
- Dangerous wreck
- A sunken vessel close enough to the surface to endanger ships, or wreckage reported in the water.
- Notice to Mariners
- The weekly publication of permanent chart corrections — the slower, permanent counterpart of a navigational warning.
- Discoloured water
- Patches of unusually coloured sea — often a sign of a submarine volcano or of a shoal.
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.