I would take those whistles off the pull straps. Seems like a good place to put them, but if you have to put the suit on in a hurry you're more likely to grab the whistle and yank... Broken cord, lost whistle. You can tie them to the pocket instead.
Might also be a good idea to invest in some water activated strobes (can clip right to the inflation tube,
Revere See-Me LED) and also some of the saltwater whistles (
Revere Rescue Whistle). Those look like the ones with the little cork balls in them? The cork will swell when exposed to saltwater, rendering it inoperable in about an hour.
Great to start the drills early!!