В вопросе выбора спасжилетов, я бы предпочел руководстоваться стандартами.
На русском сходу не нашелThe four buoyancy classes according to ISO 12402
50 N Buoyancy aid (swimming aid)
For regular swimmers near a beach or means of assistance, not unconscious. This is not a lifejacket!

100 N Lifejacket
Inland and protected waters. Not suitable for unconscious persons.

150 N Lifejacket
For use in all waters and for unconscious persons unless wearing heavy or waterproof clothing.

275 N Lifejacket
For use in all waters and for for unconscious persons, especially in heavy conditions and when wearing heavy or waterproof clothing.

PS
Есть смонадувающийся спасжилет 150N.