Not all impact vests are safety flotation devices, and vice versa.
If shopping around, for WA rules it must be at least be 50S PFD
www.transport.wa.gov.au/mediaFiles/marine/MAC-B-KiteWindsurfingSafetyEquipC.pdf For the likes of foiling/boosting... make sure the impact vest has side impact protection as well.. Many impact vest do front & back but not enough padding on the side were we typically need it.
All these are impact/50S PFDS
prowake.com.au/collections/vests Good example is the Ripcurl E-bomb/Dawn Patrol models have almost no side impact protection where the Flashbomb has heaps.
Quite a few WA foilers use the Flashbomb,