CHART 2529
NORTHERN ISLETS OF MAURITIUS

Topography. The coast alongside main land is mostly sandy beach backed by a wide coastal plain on which are several villages and plantations. There are no harbours along this coast.

Depths.  The depths are deep outside the coastal reefs which extend up to 21/2 miles offshore of Cap Malheureux (19°59'-00S 57°36'-71E). There are no charted dangers lying beyond this distance to seaward. There are some openings in the reefs which enclose a number of bays, but these are only suitable for boats.
Tidal streams. The streams off the N end of Mauritius are described at 11.188. With the E-going stream, a weaker stream sets S along the NW coast, the division of the streams occurring off Pointe Piments at LW. This then moves N until HW at Grenadiers (20°03'00S 57°31'-50E). During and after periods of W winds, the rate of the E-going stream, which sets strongly towards Canonniers Point, is greatly increased. Very little of the W-going stream is felt on the NW side of Mauritius, S of Canonniers Point. Close inshore, the stream turns about 2 hours before that offshore.

Landmarks. Poudre d’Or. Building (20°01'-30S 57°40'-86E). Hotel (20°00'03S, 57°34'-96E), standing on the E side of Grande Baie.
Major light: Flat Island Light (19°52'-92S 57°38'-99E)

Passage .  ENE of Pointe de Roche Noire (20°06'-57S, 57°44'-74E), where old black lava flows meet the sea, and: ENE of He d’Ambre (20°02'-15S 57°41'-98E), which is rugged with two peaks, thenceTo a position 6 miles ENE of Pointe Oscorne (20°00'- 61S 57°40'-99E).

Clearing bearing: From a position about 5 miles off ilot de Roches (20°17'-61S 57°49'-42E) the bearing 328° of Flat Island Light (19°52'-92S 57°38'-99E), distant about 27 miles, leads clear of the coastal reef along the NE coast of Mauritius.

Useful marks: Round Island (19°51'00S 57°47'-40E) 

Side channels
Boat channels
Between Hot de Roches (20°17'-61S 57°49'-42E) and Cap Malheureux (19°59'-00S 57°36'-71E) (11.134), the following villages are reported to be accessible from seaward through the extensive coastal reef by way of narrow and, usually, shallow boat channels.
Trou d’eau Douce (20°14'-50S 57°48'-63E).
Poste de Flacq (20°09'-10S 57°45'-87E).
Riviere du Rempart (20°06'-29S 57°41'-32E).
Poudre d’Or (20°04'-00S 57°41'-09E).
Cap Malheureux (19°59'-00S 57°36'-71E).

The coastal reef is reported to be broken by several minor openings giving access to waters within the reef and these, although much obstructed by coral heads, are navigable by boat. However, it is considered dangerous to attempt this without local knowledge.

Passage west of the islands
From a position WNW of Gunner’s Quoin, the track leads N, passing:
About 4 miles WNW of a rock, awash, situated close W of Flat Island (19°52'.60S 57°39'.40E) off the N entrance point to Palisade Bay (19°52'.63S 57°38'.94E). The island is generally flat but rises to a hill at its SW extremity.

Passage north of the islands
The E-bound track, N of the islands, passes:
of Pigeon House Rock (19°51'-76S 57°39'-47E), which can be safely passed at a distance not less than 3 cables, but should be given a wide berth of at least 1 mile by a low-powered vessel (see caution at 11.191). A boat passage exists between Pigeon House Rock and Flat Island. 
N of Nab Reef (19°49'-41S 57°47'-09E), over which the tidal streams set with great strength and the sea breaks, thence:
Serpent Island (19°49'-05S 57°48'-32E), which has light-coloured cliffs.

Passage south of the islands
Caution. Quoin Channel (19°57'-50S 57°37' 00E) (11.139) should not be used for passage S of the offshore islands, as it is obstructed by rocks and
shoals on each side and is made more hazardous by the strong tidal streams and tide-rips
Passage. The E-bound track, S of the islands, should pass:
At least 1 mile N of Gunner’s Quoin (19°56'-50S 57°37'-20E) (11.139), thence:
N of The Blacksmiths (19°56'-18S 57°37'-71E), a group of rocks close E of the N point of
Gunner’s Quoin, one of which is 1 m high. In this vicinity, the E-going stream sets with great strength. Thence:  S	of Sandringham Reef (19°53'-86S 57°40'-50E), giving the reef a wide berth as the tidal streams set with greater strength over it, thence: N of Mapu Patch (19°58'-75S 57°40'-20E), an isolated coral patch, thence:S	of Rip Bank (19°54'-25S  57°41'02E), over which the sea breaks occasionally, thence: Either: SSW of Abbe Bank (19°55' 08S 57°46'-11E), over which the sea sometimes breaks or  N of La Caille Bank (19°54'-25S 57°46'-88E), over which the sea breaks when rough or in heavy swell, and  S of Round Island (19°51' 00S  57°47'-40E), which is the highest of the group. Clearing line. The alignment (251°) of Cap Malheureux (19°59'00S 57°36'-71E) with the old lighthouse on Canonniers Point (20°00'09S 57°33'-16E) passes close S of Abbe Bank.

Passage east of the islands
From a position about 6 miles ENE of Pointe Oscorne the N-bound track, E of the islands, passes:
E of Abbe Bank (19°55'-08S 57°46’HE) and:
E of La Caille Bank (19°54'-25S 57°46'-88E)thence: 
E of Round Island (19°51'-00S 57°47'-40E) thence:
E of Serpent Island (19°49'05S 57°48'-32E)
keeping well clear of a rock, awash, close E of the island.
Clearing bearing. The bearing 009° of Serpent Island, open its own breadth E of Round Island, passes E of the banks.

GABRIEL AND ROUND ISLAND
Description. A number of islands lie on a steep-to bank which extends NNE from Mauritius. The waters surrounding these are moderately deep and have no charted dangers with depths less than 13 m more than 1 VA miles from the islands in the wide navigable channels between them.

Natural conditions
Tidal streams. See information on the chart. The E-going stream begins about 51/2 hours before HW by the shore and lasts for 6 hours. The stream then sets W for 6 hours with no period of slack water. As indicated on the chart, the streams are strong. During spring tides, they attain rates from 4 to 5 kn although, at neap tides, the rate seldom exceeds 2 kn. The streams are stronger at night than during the day. During and after W winds, the rate of the stream setting E round the N end of Mauritius is greatly increased. On the bank among the islands, during strong S winds, the E-going stream is deflected NE.

Tide-rips. These are dangerous and extend up to 3 miles from Gunner’s Quoin (19°56'.50S 57°37'.20E) with the E-going stream. Rips also form in the vicinity of Flat Island (19°52'.60S 57°39'.40E). 

Landmarks:
Building (20°01'.30S 57°40'.86E).
Hotel (20°00'.03S 57°34'.96E). standing on the E side of Grande Baie

Caution should be exercised when approaching the bank off the N end of Mauritius from N, as depths shoal rapidly off the dangers N and NW of Round Island (19°51'-00S 57°47'-40E). Elsewhere, sounding over the bank should give adequate warning of the proximity of dangers. Low-powered vessels approaching from E during the E-going tidal stream should pass N of the islands to avoid the strong streams among them. 

Guner’s Quoin
The Blacksmiths (19°56'-18S 57°37'-71E), a group of rocks close E of the N point of Gunner’s Quoin, one of which is 1 m high. In this vicinity, the E-going stream sets with great strength.

Flat and Gabriel Island. Flat Island (19°52'.60S 57°39'.40E) lies 31/2 NE of the Guner’s Quoin and is generally flat but rises to a hill of height 102m at its SW extremity. Flat Island Light (white concrete tower, red lantern, 16 m in height) (19°52'.92S 57°38'.99E), situated on a high promontory at the SW end of Flat Island. At the W end, there is Palisade Bay and the coast is stony and cliffy. NE coast is covered by Sandringham reef, which is continuous to Gabriel Island (19°53'.14S 57°40'.38E). Gabriel Island lies 4 cables SE of the Flat island and separated by a coral reef. Anchorage may be obtained S of Flat and Gabriel Islands in 12 m, sand and coral, with Flat Island Light bearing 312° distant 1 miles. The berth lies on the alignment (060°) of an islet, 2 m high, situated close off the S end of Gabriel Island. Pigeon House Rock (19°51'-76S 57°39'-47E) lies 3 cables N of the N end of Flat Island and 52 high.  A boat passage exists between Pigeon House Rock and Flat Island.

Passages between the islands
The N-going track between the islands passes:
E of The Carpenters (19°57' 02S 57°37'-76E), a group of rocks, awash, close SSE of Gunner’s Quoin, over which the E-going tidal stream sets with great strength and on which the sea breaks heavily, thence:
E of The Blacksmiths (19°56’T8S 57°37'-71E)
thence:
W of Abbe Bank (19°55'08S 57°46'-11E)
,thence:
W of La Caille Bank (19°54'-25S 57°46'-88E)
and:
E of Rip Bank (19°54'-25S 57°41’ 02E) (11.193).
Once clear of Rip Bank, the track passes:
E of Gabriel’ Island (19°53'-14S 57°40'-38E), thence:
W of Round Island (19°51'-00S 57°47'-40E)
Thence
W of The Blinder (19°50'-56S 57°46'-49E), a reef situated about 2'A cables NW of Round Island, over which the tidal streams set with great strength and on which the sea breaks occasionally, thence:
W of Nab Reef (19°49'-41S 57°47'-09E).
	
Clearing bearing. A line of bearing, not less than 235°, of Canonniers Point old lighthouse (20°00' 09S 57°33'-16E), open well S of Gunner’s Quoin, passes SE of Rip Bank.
Anchorage and landing

Flat Island 
Anchorage  may be obtained S of Flat and Gabriel 1 Islands in 16 m, sand and
coral,with at Island Light (11.189) bearing 312° distant 11A miles. The berth lies
on the alignment (060°) of an islet, 2 m high, situated close off the S end of Gabriel Island (11.195), with the summit of Serpent Island (11.192), 8% miles NE. Care must be taken to avoid a drying rock about 21/2 cables NE of the charted berth.
As the sea rises quickly during S winds and the holding ground is not good, vessels should leave the anchorage at the first sign of strengthening wind.
Mooring. There is a mooring buoy (black and white, conical) about 21/2 cables NW of Flat Island Light, in Palisade Bay

Round Island 
Landing may sometimes be possible at two places on the W side of Round Island (19°51'00S 57°47'-40E), which is otherwise inaccessible
Round Island (19°51'.00S 57°47'.40E) is 280 m high and the highest of the offshore group. The island is shaped like a rounded haystack and is barren except for a few palm trees. If cloudy, or when the horizon is obscured, it may be seen before Mauritius itself. Round Island and Serpent Island (19°49'.05S 57°48'.32E) are reported to be easily identified on a radar display. Landing may sometimes be possible at two places on the W side of Round Island (19°51'00S 57°47'-40E), which is otherwise inaccessible. Serpent Island (19°49'.05S 57°48'.32E), lies 11/2 miles NE of the Round island. The island has light-coloured cliffs. Nab reefs having least depth 4.9 m, lies 1 mile W of the southernmost end of the serpent island. The Blinder (19°50'-56S 57°46'-49E), a reef situated about 2 cables NW of Round Island, having least depth 0.7 m over which the tidal streams set with great strength and on which the sea breaks occasionally
Round Island is an offshore islet, situated 22.5 km off the north-east coast of Mauritius. It is the second largest of Mauritius offshore island with an area of 219 ha. RI was classified as a Nature Reserve in 1957 and is under the administrative control of National Parks and Conservation Service (NPCS) and the Mauritian Wildlife Foundation (MWF).
The island is a volcanic cone mostly made up of tuff (comapcted and friable volcanic ash), dating between 25000-100000 years. Slopes are generally steep, particularly on the upper part of the island. The island is mostly covered with bare rock.
Round Island is famous for its reptile community. Nine species of reptile are found on the RI. Round Island is also an internationally important island for seabirds. It has the only hybrid breedinig colony of three Petrel species. Unlike many small ropical oceanic islands around the world, RI has still retained many of its original elemens and ishe only relatively large island, in the Mascarene group, free of introduced mammals and reptiles.
MWF has restored permanent wardens on RI that have the day-to-day responsibility of running the island. Strict quarantine procedures are laid down for entry into the Round Island. Adherence to the laid down instr