Signal mirror success story, 12/29/2019:

Sailboat with 3 aboard in the Pacific.

First it was dismasted, and the next day a storm turned it upside down and flooded the engine, navigation electronics and satellite phone. They tried in vain for days to get the engine or phone working again.

Eight days after their phone died, a vessel passed within 1/2 mile, and they used their rockets and smoke bombs in a vain attempt to get its attention.

The next day another vessel appeared "a long way off".

"So we ripped the mirrors from the bathroom and used them to reflect the sun to signal the ship." (quotes from survivor's account)

As the US Coast Guard commented afterwards, an EPIRB/PLB would have greatly shortened their ordeal.

News Story - Daily Mail

Survivor's Account - Outside Magazine

Not sharing my obsession, many accounts failed to mention the mirrors:

US Coast Guard News Release

Family day by day account for the 9 days