Thanks P.M.
The correct method of donning the lifejacket shall be reasonably self-evident to untrained passengers. The lifejacket shall be made to fit securely throughout its range of adjustment in all likely conditions of use and size of wearer. So far as possible, any adjustment necessary to make the lifejacket fit securely shall be made automatically when being donned. The wearer shall be able to make any re-adjustment without undue risk of the lifejacket slipping off. The lifejacket should be capable of being removed from the valise or container and donned by an adult passenger, seated in an aircraft, within 15 seconds unassisted, with a safety belt fastened.
Blimey. Hard to see the 2nd half of those statements being carried out with 'tape' type jackets. Worth me having a go next week during turn-round.