I vote yes!

Typically it's just buoyancy vests, true.

Well the "Buoyancy Compensator" is practically a life vest... in fact older models were pretty much the "horsecollar" style like you'd see with a Mae West looking inflatable life vest.

Then again as she's swimming with what looks like a airliner style one, she probably has weights to perfectly balance herself to neutral buoyancy for easy swimming, with the life vest in case there's an emergency.