Many posts and little science so here is something to feed the brain...
Short answer:
Lew Nuckols:
Uncompressed foam neoprene has an insulation value of approximately 3 CLO per inch thickness. A typical 6 mm wetsuit (approx 1/4 inch thick) has an insulation value of approximately 0.75 Clo when submerged at the surface, but due to compression drops to less than 0.25 Clo at 100 FSW.
A method to calculate the insulation value as a function of depth and foam density and table of values for wet and dry suits:
U
w = Suit Conductance (Heat transfer coefficient)
R
l = resistance to heat flow through thin film of water
R
f = resistance to heat flow through foam neoprene
R
conv = convective heat transfer between suit and surroundings
as seen here:
from:
Nuckols, Marshall L. Life support systems design : diving and hyperbaric applications / M.L. Nuckols, Ace J. Sarich, Wayne C. Tucker. Needham Heights, MA : Simon & Schuster Custom Publ., c1996.
Since your wife has loosed the purse strings, make sure you consider that insulation must work when flooded as well has have a proper fit.
from:
Proceedings of the DCIEM Diver Thermal Protection Workshop.
Edited by Nishi, 1989
RRR ID: 3922, DCIEM 92-10