Drysuits, regardless of what they’re made of, are designed to fit loosely. The baggy fit allows for some freedom of movement and leaves enough room for layering undergarments that will keep you warm.
Ease of movement typically isn’t a problem; drysuits and wetsuits are made with watersports in mind, after all. But – there’s always a “but” – the drysuit’s loose fit can create a lot of drag in the water, affecting your ability to swim.