Warning sign image by Clker-Free-Vector-Images from Pixabay
1. Know what drowning looks like
"Drowning doesn't look like drowning" highlights that drowning is usually a deceptively quiet event with minimal thrashing and yelling. If someone isn't moving or can't respond, get them out of the water or get help immediately.
2. Know your fire exit(s)
Fire exit image by wiredsmartio (https://wiredsmart.io/), downloaded from Pixabay
If you're staying in a hotel with my mum she'll expect you to have your shoes ready near the door just in case ;)
3. Read the safety card information
Trains and aircraft tend to have big complicated doors that are quite a palaver to open (for good reason). They're not all opened in the same way either - if there's information to hand telling you what to do (and when) if there's an emergency, read it. It's much more relaxing to do this before any emergency happens!
4. Know the local emergency phone number
It's 999 in the UK but what should you dial if you're in another country? Here's a list of emergency telephone numbers from Wikipedia, with general country by country safety advice from the UK Government's Foreign Travel Advice pages, and their foreign travel checklist which includes advice to make a note of your passport number and know how to contact your relevant embassy / consulate.
I shared the original post above with Mumsnet and a couple of other suggestions came in which I've now added below.
5. Rip tides aka rip currents
Reassuring advice from RNLI on what a rip current is, how to spot one and - if you've not avoided it, how to get out by floating away from it then swimming parallel.
See also their general beach safety advice (what the flags mean, don't use inflatables as they can sweep you out further to see if the wind comes up).
6. Float to live
From the RNLI's Respect the Water site - fight the urge to panic and thrash, lean back, extend your arms and legs and float, catch your breath and call for help or swim from danger if possible.
Note: I posted this last week to the Buzzfeed Community and it was deleted a day later (in fact my account was deleted) because it was deemed to have been too self-promotional. I think this is a pretty odd decision. Fortunately I was able to uncover a cached copy so here it is.
[Things to add for next year's version - human error is ubiquitous and not all of it can be 'trained away'!]]