The two piece Arctic Set from Fourth Element is a great option to keep you warm and comfortable under your drysuit in those waters that aren't quite so warm. 

The top is designed with a long body to ensure this overlaps with the trousers, ensure this is tucked into the bottoms before donning your drysuit to prevent separation. Thumb loops prevent the sleeves from riding up, but make sure you remove them and tuck them back inside your wrist seals before getting in the water!

The leggings feature secure foot loops to prevent movement while getting into your drysuit and a high waistband for overlap with the top. The lower legs are single layered to prevent bulk. 

The Arctic Undergarments from Fourth Element are designed with warmth and comfort in mind, tested in the harshest conditions by the Norwegian Navy and British Antarctic Survey Dive Team. Moisture wicking, high insulation fabric give you excellent thermal protection with reduced bulk. The garments are designed to reduce air flow around the body by holding air within the fabrics fibres dramatically reducing the rate of cooling. 

The outer layer is water resistant and retains a huge amount of its thermal properties when wet so many divers have not even noticed leaks from wrist and neck seals until after they have surfaced from their dive.