Spume

Spume - Foam, froth, frothy matter. The spume is present in huge amounts after the recent storms.

From the Old French spume or the Middle English Spome. For example:

1390 J. Gower Confessio Amantis II. 265 Sche sette a caldron on the fyr,..And let it buile in such a plit, Til that sche sawh the spume whyt.

Back in 2012 a ferocious onshore storm covered the streets of the village of Footdee with spume. You might like to view the scene!