Worked as a carpenter, boat builder and navigator. Jacques was at Port Toulouse in 1750 where he built a vessel of 35 tons. He is probably the "Old Coste" that is mentioned in the journal of Charles Robin, a trader from the Isle of Jersey, doing business in Arichat.
Jacques remained in Port Royal where most of his lineage remained
According to Bono Arsenault's " The History of the Acadians" Jacques was at Port-Toulouse in 1752 working as "d'habitant constructeur."
In the 1752 census, he had 2 oxen, 3 cows, 2 pigs, 11 horses, one boat and one skiff (esquif)
The LaRouque census shows him living with his wife and son at Port Toulouse in 1752.
He was a carpenter, navigator, and coastal trader and is also recorded as having built a vessel of 35 tons at Port Toulouse in 1750.
After 1752, he went to live on Ile Madame at what is now Petit de Grat.
He was living in Canso in 1765 and the journal of Charles Robin states that he was alive in 1768 at which time he was living at Arichat.
The Isle Madame Historical Society has records referring to a Capt. DeCoste who owned a 35 ton vessel which presumably would have been Jacxque.
They also have a map showing original land owned by the Coste family on Isle Madame.
A map of the original landowners on Isle Madame showed the Girroir family and Coste family as owners of adjoining property.