Dangers and cautions

Mariners should navigate with extreme care. By day. Provided the sun is high and behind the observer all the channels between the atolls and even those amongst islets or reefs, may be passed through without anxiety as below-water coral dangers will be visible from the masthead. However, extra care should be taken at periods of spring tides when strong rips and eddies in the reef entrances make below-water hazards more difficult to be seen.

By night. Many light-beacons are erected on the reefs and atolls for use by local fishermen; these lights are of limited range and may not be visible from the middle of the wider channels.

Except for the reefs surrounding Addoo Atoll, Huvadhoo Atoll and Foam Island, there no known dangers in Equatorial Channel.

From SW or W Thinadhoo islet may appear as the N point of the atoll because none of the low-lying islets situated farther N of it are wooded.

The area in the E approaches to Kuda Kalhi is unsurveyed. Bodu Kalhi (416N, 7333E), the best and widest entrance into the lagoon of Male Atoll lies between Kaduoiygiri and Lankanfinolhu, 1 ¾ miles NNE; the channel is about 1 ¼ miles wide between the refs. There are depths of about 50 m in the deepest part of the fairway which lies 6 cables S of Lankanfinolhu Islet and about 3 cables clear of its reef; a bank with depths of 10 m or less extends 5 cables into the entrance N from Furanafushi.

Between Himmafushi (418 6 N, 7334 3E) and Lhohifushi, 3 ½ miles NE, there are several entrances into the lagoon which are reported to be well defined but they are all generally narrow and some are encumbered with shoal patches as shown on the chart.

Thulusdhoo Kandu (422 7 N, 7339 2 E), the N-most entrance on this side of the atoll, lies between Thulusdhoo and Viligili, 5 cables ENE; the channel is about 2 cables wide with a least charted depth of 35 m in the approach from SE. Within the lagoon the line of the fairway leads to deep water but there are reefs close SW of this line.

Male and its adjacent islands may not be detected on radar until after a visual landfall has been made. Several islands are conducting reclamation or construction work and radar ranges should be verified carefully.

Gaadhoo Koa is the recommended daylight approach to the anchorages N of Male for all vessels, except those of very low power which normally use Bodu Kalhi. However, Gaaadhoo Koa has proved to be increasingly dangerous for shipping with the seasonal monsoons causing strong currents that set across its mouth at a reported rate of up to 6 kn; night navigation of the channel is not recommended. There is considerable high speed and small craft passenger traffic, which crosses the entrance channel, between Male Island and Hulule Harbour, see note on chart.

Anchoring less than 3 cables N of the breakwater is not recommended, especially during the NE monsoon, because of the strong currents experienced in that vicinity.

There are areas surrounding this part of the atoll which have not been surveyed; mariners are advised to give these areas a wide berth.

ODAS buoys may be encountered between and well to seaward of these islands, and area subject to movement.

The channel is generally very deep and free from charted dangers. However, an area with two depths of less than 100 m, reported in 1985 and 1986, lies about 34 miles NNW of Ihava Atoll.

Vessels have grounded and been wrecked on Minikoy Island apparently due to having shaped a course to pass a few miles N of Minikoy Island Light. In some cases, after sighting the light from E instead of passing south of it where the light provides a useful guide, vessels have steered to pass N of it, where from E and N it is partly obscured by the densely wooded island.

Because of this, and also because of unpredictable strong S sets encountered at times, the practice of shaping a course to pass only a few miles N of Minicoy is dangerous, especially at night.

In January the sea is rough, vessels bound NE should remain well offshore and clear of dangers along the SE coast of Sri Lanka. In March the sea is much calmer.

There are many rocky heads on Little Basses Ridge, particularly towards the SW end, on which the sea often breaks. The sea may break on any part of the ridge with a moderate swell where depths do not exceed 5.5 m, and probably in greater depths.

Only light draught vessels should attempt to cross any part of the ridge, passing between 2 and 6 miles SW of Little Basses Light, noting the existence of the stranded wreck.

An area of shoal ground, with irregular depths, lies NNW of Little Basses Reef and vessesl should not approach within 1 ½ miles of the reef with Little Basses Light bearing between 148 and 185. If a close approach is required from a position NW of the reef, vessels should close the lighthouse between bearings of 134 and 109 only.

Depths beyond the E end of Little Basses Ridge, 1 ½ miles NE of the lighthouse, are irregular and overfalls occur.

A number of unexamined rocks and shoals within the 20m depth contour lie off the coast between Elizabeth Point (838N, 8113E) and Pulmoddai Roads, 22 miles N. Other uncharted dangers may also exist both farther offshore between Elizabeth Point and Pulmoddai Roads and farther N between Pulmoddai Roads and Mullaitivu (0916N, 8049E).

It is advisable to remain in depths of more than 40 m by day and more than 50 m by night, or in thick weather, between Elizabeth Point and Mullaitivu.

Vessels should avoid passing through the area of the above shoals, and in thick weather area advised give it a wide berth.

Large vessels should not navigate off this coast, N of latitude 815N, in depths less than 35 m because the area is imperfectly surveyed and is a fishing ground.

The attention of small vessels coasting is drawn to:

An area of foul ground and rocks, over which there are heavy breakers during the NE monsoon, extends 3 miles offshore between Manappad Point and a position 5 miles NE. And:

Numerous shoals and rocks, over which the sea breaks in heavy weather, lie up to about 2 miles offshore between Tiruchedur Point and a position 7 miles NNE.

2. Learn by heart the following words, word combinations and abbreviations

Terms

1. Danger line – граница опасности

2. Rock (islet) which does not cover, height above height datum – Надводная скала (камень) с обозначением высоты

3. Rock which covers and uncovers, height above height datum – Полностью покрывается при полной воде, высота дана над нулем глубин

4. Rock awash at the level of chart datum – Скала, осыхающая при уровне, соответствующем нулю глубин карты

5. Dangerous underwater rock of uncertain depth – Всегда под водой, глубина неизвестна

6. Dangerous underwater rock of known depth – Всегда под водой, глубина известна

7. Outside the corresponding depth area – Меньше диапазона окружающих глубин

8. Rocky and coral reef, which awash – Осыхающий риф, скалистый и коралловый

9. Underwater coral and rocky reef – Подводный риф, скалистый и коралловый

10. Non-dangerous rock (islet) depth known – Подводная скала (камень), глубина над ней более 20 м

11. Bank, depth contours not shown on chart – Банка, которая не показывается изобатами

12. Breakers (Br) – Буруны

13. Shallow – Mель

14. Underwater volcano with depth and year of the latest eruption (Sub Vol. (1968)) – Подводный вулкан с обозначением глубины и года последнего извержения

15. Underwater mountain – Подводная гора

16. Underwater fulls (sandwaves) – Подводный береговой вал

17. Weed (kelps) – водоросли

18. Pack ice limits – Границы распространения паковых льдов

19. Rigid ice limit – Граница распространения неподвижных льдов

20. Obstruction, depth known (Obstn 11₂) – Подводное препятствие, глубина известна

21. Fish havens and oyster banks (submerged structures for breeding of fish, oysters, mussels, etc.) – Рыбные и устричные банки (сооружения, затопленные с целью разведения и выращивания рыбы, устриц, мидий и т.д.)

22. Fishing stakes, nets – Рыболовные сети, частоколы

23. Fish trap – Рыбные ловушки

24. Grounded hummock – стамуха

25. Iceberg (Berg) – айсберг

26. Wreck showing any portion of hull or superstructure at level of chart datum (Wk) – Затонувшее судно с частями корпуса или надстройки над водой

27. Wreck, covers and uncovers (Wk) – Затонувшее осыхающее судно

28. Submerged wreck, depth known (Wk) – Затонувшее судно с обозначением глубины над ним

29. Submerged wreck, depth 20 m or less (Wk) – Затонувшее судно с глубиной над ним 20 м или меньше

30. Submerged wreck, depth more than 20 m (Wk) – Затонувшее судно с глубиной над ним более 20 м

31. Wreck showing masts above water (Mast) – Затонувшее судно с мачтами над водой

32. Wreck, least depth known by hydrographic trawling – Затонувшее судно, глубина над которым подтверждена гидрографическим тралением

33. Wreck, least depth unknown but considered to have a safe clearance to the depth shown – Затонувшее судно, глубина над которым приблизительна

34. Foul ground and depth over it if known (Foul) – Нечистый грунт и глубина над ним, если известна

35. Submerged obstruction, depth known by hydrographic trawling (Obstn)– Подводное препятствие, глубина над которым подтверждена гидрографическим тралением

36. Obstruction, depth unknown (Obstn) – Препятствие, высота над которым неизвестна

37. Doubtful obstruction (Obstn) – Препятствие, существование которого сомнительно

38. Approximate or doubtful obstruction (Obstn) – Препятствие, положение которого приблизительное или сомнительное

39. Reported obstruction with the date of report (Obstn (1976)) – Объявленное препятствие с указанием даты объявления

40. Stumps of posts or piles, wholly submerged – Обломки столбов или свай, полностью затопленные

41. Submerged pile, stake, snag or stump (with exact position) – Затопленные столб, свая, обломки

42. Eddies – Водовороты

43. Overfalls and tide-rips – Спорные течения, толчея, сулои