The gig rounded a point of Ford Island and headed into the western channel.
The western channel's depth was found to be too shallow by 1906 when the steam barge Resolute sank outside the harbour during a storm.
Wainfleet Clough Outfall is on the western channel, which is tidal below the sluice.
It was erected in 1862, marking the western channel.
Local television cable operators pulled out western channels such as BBC World News to deter what they called "anti-Pakistan bias" in the media.
The western channel is deeper (up to 227 meters) and narrower than the eastern channel.
It had come ashore but a little distance from the western channel, by which the sea flowed in and out of the bay.
There is a surface current inwards in the eastern channel, but a strong undercurrent outwards in the western channel.
These guns began firing during the afternoon and by 20:00 Troude had given orders for his squadron to sail through the western channel during the night.
The western channel, or Dact-el-Mayun, has a width of about 16 miles (25 km) and a depth of 170 fathoms (310 m).