Hi,
Note that the "British pound" isn't a unit of weight (lb.) but rather a unit of currency. By weight, the lb. is the same (British or American), though Brits usually use grams or kilograms rather than pounds, for weight.
The currency conversion from the British pound (£) is roughly equal to $1.22
The answer is friction. As ocean wave approach the shoreline, they are affected by the sea bed through process such as refraction, shoaling, bottom friction and wave-breaking. However wave breaking also occurs in deep water when the waves re too steep. If the waves meet major structurer or abrupt changes in the coastline, they will be transformed by diffraction.
Pollution and smoking... Hope it helps, have a great day!
