Abstract: A liquid-insulated garment supplements the inherent thermal protection va of traditional suit insulations in conventional passive diving suits with bladders containing insulating liquids having substantially the same densities as water and thermal conductivities of less than 0.070 Btu/ft-hr.degree. F. to provide insulation from ambient cold. The additional thermal protection created by the liquid-insulated garment helps the diver surpass the performance and acceptable duration constraints imposed by conventional drysuits or wetsuits and allows easy adjustments to the level of thermal comfort required by the diver. It additionally reduces the inherent buoyant forces associated with conventional drysuits and wetsuits, and provides uniform thermal protection over the entire surface of the diver's body since it is tailored to fit the diver.