Here is the size chart for selecting a Watery Pelican wetsuit for men. The measurements are taken with the suit lying flat and without stretching. The wetsuit expands during use and in water, allowing it to adapt to the body while swimming. Choose your size based on the measurements closest to yours.
If you're in the unfortunate position of being between two sizes, opt for the one where you match the most measurements. Generally, the most important measurements are chest and height (ankle to shoulder).
A wetsuit should not fit too loosely; if there are many air pockets or “wrinkles” around the suit, it is too large for you.