TYE AND SUALIB. 251 
found eleven fathoms of water. Lieutenant-Commandant Ringgold 
believes that it extends for several miles. There is plenty of water on 
most parts of it for any class of ships, though it would be well to avoid 
it, as there may be some coral knolls that might bring a ship up. A 
current was found here setting to the north a mile and one-eighth 
hourly. 
The next day the Duff Reef was examined, as well as the sea, for 
about thirty or forty miles to the east of it, but no other dangers were 
visible. The Duff Reef has an extensive sand-bank on it, and the 
island of Vuna is plainly visible from it. 
The island of Yalangalala, which lies just to the westward of the 
Duff Reef, has an extensive reef. It is uninhabited, and forms, with 
Velerara, the southern side of the Nanuku Passage—the island of 
Nanuku and its reef forming the northern side. This passage between 
these islands is ten miles long; the course through is southwest. The 
islands to the north of this passage are small and low, and sur- 
rounded by very large and extensive reefs. The most northern of 
these are Korotuna and Nukulevu, both of which are low, covered 
with trees, fertile, and have many inhabitants. 
Nukumanu and Nukumbasanga lie to the southward of these; they 
are almost united by reefs and sunken patches of rock, which extend 
to the Nanuku Reef, and round to Lauthala and Kambia. 
Too much precaution on the part of mariners cannot be used in 
approaching this part of the group. Several times during the survey 
the Porpoise was in great danger. The currents and tides are irregu- 
Jar and much governed by the winds, and at times are found running 
with great velocity through the various and contracted passages. 
After making these examinations the Porpoise went to Tasman’s 
Straits, or to those to which I have assigned that name, under the 
belief that they are those discovered by that navigator. They lie 
between Vuna and Kambia. This strait was examined, and though 
contracted, affords a safe passage. Although I was able to identify 
Tasman’s Straits, his Hemskirch I was unable to make out. There 
is a fine harbour on the Vuna side called after Tubou the pilot, which 
the brig reached on the afternoon of the 3d of July, having dropped 
her boats the evening before to pass round Lauthala and Kambia. 
The boats joined her previous to her entering the straits, having passed 
the night in a small bight off the island of Kambia. 
Tubou Harbour is well protected except from the north winds; it 
is formed by an extensive reef and sand-bank. The 4th of July was 
spent here, but not in festivity, for Lieutenant-Commandant Ringgold 
deemed the weather too fine to lose; so the survey of the straits was 
