That’s why I have, DSMB, Dive Alert, PAB & PLB.
DSMB
As you mentioned in Where do I put my (D)SMB? about launching DSMB at depth, as soon as you get blown away by current.
Dive Alert
In such squalls loud sound may be helpful to use.
PAB
For faster response within VHF range as planned with the liveaboard crew.
PLB
For alerting device as the last resort, when other alerting devices fail.
Have you actually tested a dive alert at distance? The sound - like the dive alert - is very much line of sight. By the time anyone can actually hear you (in swell or rain) you're practically next to the boat. Depending on how loud the boat is, effective range on water is a max of 400m. Nowhere near the mile they claim. Save space and money and air - get a whistle instead.
Or you could save money, space, doesn't do squat for non-AIS equipped boats, can't be used by hikers or anyone on land - and skip the Nautilus.
The one thing that you can do to help be found more important than all this technology? Make sure the boat has binoculars aboard. Many small vessels do not.