Deffo need to try them on fully clothed, the shops arent going to have hassle with you trying them as they have to be comfortable, Im XL and my flotation is XXL this gives me plenty of room for casting, wearing heavy clothes underneath, getting the thermal wellies on, and bending over to bait up. remember when trying it on to bend and move they way you would when out fishing

ALSO NOT ALL Flotation Suites are waterproof check before you buy!.. nothing worse then being nice and warm and soggy on a beach in winter thinking ..I thought this was waterproof!!