Guido Blokland's Page

A little known maritime disaster occurred outside Stornoway Harbour in the early hours of New Year's Day 1919. H.M.Y. Iolaire struck rocks on the Beasts of Holm reef at 1.55 am, and sank. The weather was poor, with strong winds and a heavy swell running. Only seventy-five island sailors, mainly Royal Navy and Royal Naval Reserve personnel, survived. Two hundred and five drowned, of whom more than 60 were never recovered from the sea. More details on this webpage.
This tragedy struck a blow, registering even more painfully, coming as it did just after the end of a bloody war, in which more than 1,000 islanders had died. The men on board Iolaire were eagerly awaited in their home villages, but many never returned.

This is one of the worst maritime disasters in British waters in peacetime, second only to the sinking of the emigrant ship Norge in 1904 at Rockall, where 700 perished. And I'm sure you did not know about that one either. But the loss of the Norge lies outwith the remit of this forum.