links to singing by Norrie MacÌomhair,Sineag Nic an t-Saoir, and Maeve McKinnon are at https://www.bbc.co.uk/alba/oran/orain/laoidh_an_iasgair/
This song is an invocation for a safe journey
The words are by Fr Allan McDonald (aka Ailean Dòmhnallach) 1859-1905. Fr McDonald was born in Fort William. He became a priest in 1882, and served in Oban, South Uist and Eriskay. He was an activist for tenants' rights and a scholar of folklore and Gaelic language https://en.wikipedia.org/wiki/Allan_MacDonald_(poet)