It’s not enough to know where the life jackets are on board, you need to know you’ll be able to get to them in an emergency.
I read this morning that one man is missing, believed drowned, after jumping off a boat that had caught fire. A portable propane heater caused the fire. Two other men were rescued, only one of whom was in a life jacket. The life jackets that were stowed in the bow could not be reached through the fire.
I remember the case of a yacht being sunk by a careless hydrofoil. No one on board had time to get to the life jackets. The result was that that skipper, from then on, kept his life jackets in a cockpit locker, where they were easiest to get at.
I do not advocate that we should wear life jackets at all times, but there are occasions, such as crossing a bar in or out of port, when it is advisable for all crew to have them on. In some places this is a legal requirement.
It’s a matter for you, as skipper, to assess the risks involved in what you are doing and then instruct your crew.
Learn more about Safety and Emergencies in The Boating Bible Manual of Seamanship.