What's the difference between a Type III foam PFD and a Type V inflatable?

Type III foam vests provide constant buoyancy the moment you hit the water and don't require maintenance beyond inspection, but they're warmer and bulkier. Type V inflatables are low-profile and cooler to wear but only provide flotation once activated (either automatically or manually via ripcord), require annual CO2 cartridge inspection, and many are not rated for non-swimmers or whitewater. Most inflatables are USCG-approved only when worn.