Shakespeare Bivvy - Double skin construction from 1000mm PU coated nylon taffeta offers total waterproof protection with the added benefit of minimal condensation.
The flysheet is 190T PU coated polyester with taped seams giving a hydrostatic head of 1500mm.
The skin is made from military standard, heavyweight PU coated waterproof nylon.
The kinetic energy per cubic centimetre is 2 pu t, where is the density and u is the velocity of disturbance due to the passage of the wave.
We also have pu t =p o u t /(I +dy/dx).