I am not sure kha khun Oum, they call 'fjord' (mai na ja chai lake naa). You can swim kha but only along the coast (mai nao tai..in summer kha) but in winter!!! Nao nao tai nae nae..5555. Just kidding na kha in winter they close, too much snow.
You Can Try Without Succeeding. But You Can Not Succeed Unless You Try!