They were extraordinarily big and deep low pressures that drove powerful winds and big seas, day after day, week after week. Some old boys in Scilly said they'd never seen seas to the west like it. Here on St Martin's we're lucky as we don't get SW or W seas too bad, being sheltered by Tresco (and Bryher and Samson).
Looking back through recent history, it appears the bank actually used to be at least 15 feet further out again. Along the west'ard end of Lawrences fields the public track runs inside the hedge line. But in this line of Pittosporums are walls and gate posts; it's evident from this and local knowledge that the track used to be outside where the Pittosporums are now. If you were there now you'd be on the beach!
All this makes me think of the impermanence of these islands, how we need to continually adapt and take the threats of climate change and sea level rise very seriously indeed.