REMARKS ON THE TIDE TABLE. 287 



(4.) Bristol Channel. — The Tides of the Bristol Channel are remarkable 

 for their magnitude and rapidity. There are few places in the world where 

 they are exceeded. The Bay of Fundy, Nova Scotia, and the Bay of Mont 

 St. Michel, on the French coast, are somewhat analogous. The effect of 

 these rushing watera is to alter the channels and shift the banks in the 

 upper portion of the Bristol Channel in a most extraordinary manner. 

 Some idea is given in our Sailing Directions for the Bristol Channel. 



Outside the Bristol Channel, spring tides rise from 22 to 24 and 26 feet; 

 but as that channel narrows, or contracts in its breadth, the velocity and 

 vertical rise increase in proportion ; and so much that, in King Road, it 

 rises to the height of 40 feet and upwards.* Between Nash Point and 

 Bridgewater Bay, past Hurlstone Point, &c., the Tide sets with great 

 velocity over the Culver Sand, into Bridgewater Bay and River. Through 

 Caldy Sound, the stream from Caermarthen Bay makes Westward nearly 

 two hours before the flood has done running without the island ; and the 

 stream makes Eastward through the sound, as well as between the Hel- 

 wick Sand and Worm's Head, nearly two hours before the Channel ebb 

 ceases. 



At Lundy Island, ordinary spring tides rise 27 feet, equinoctial springs 

 31 feet, and neaps 13 feet. In Barnstaple Bay, ordinary springs rise 25 feet, 

 equinoctial 28 feet, and neaps 15 feet. In this bay, at from 2 to 3 miles 

 from shore, a gentle stream sets to the Eastward, from the time of low 

 water to four hours flood, and then to the Westward until low water again. 

 In mid-channel, between this bay and Lundy Island, the streams of flood 

 and ebb set tide and tide each way, according to the time of flowing on 

 the shore, at the rate of 3 miles an hour on springs and 2 miles upon the 

 neaps, allowing half an hour for slacking and veering out. 



It should be understood that, within the range of Swansea Bay and its 

 oflBng, at about 5 miles West of the Scarweathers, the first-quarter flood 

 sets directly toward them ; after which, and until half-flood, it sweeps 

 1 mile outside, nearing the West end of the Nash Sands ; and ultimately 

 setting, till high water, S.S.E. by compass, which points well outside of 

 all. It averages a rate of 4 and 5 knots on springs,. and 3 knots upon 

 neaps, and changes exactly at the same time that it ceases to rise on the 

 shore ; but slack water always lasts half an hour. 



It has been observed that, over the shoals, and through the different 

 channels, the velocity of the tides is greatly increased, and there is reason 

 for believing that on springs the rate is nearly 6 knots. 



There is always a strong tide under these shoals, which is, of course, 

 increased or decreased according to the vertical rise. This is of consequence 

 when working up near them, as some advantage may, in the daytime, be 

 taken of it, by keeping on the proper side. Its influence will be manifest 

 to any vessel thus situated, as she would nearly make her course good 



• Captain Andrew Livingston, et Liverpool, to whom our eailier editions of this work 

 were much indebted for many valuable and useful communications, informed us 

 that he actually measured fully 50 feet rise of water, in November, 1813, at King Road, 

 in a spring tide. At Chepstow, above, on the opposite side, the vertical rise of a spring 

 tide also averages 50 feet, not uncommonly attaining 60 feet, and has even been known 

 to reach 72 feet. 



