just in case you havn't seen info by Constance radcliffe in 'Ramsey 1600-1800' -
VOAST (or Voste or Vaust)

This name has a history of at least 200 years in the Island. It first appears
in Castletown in 1658, when a Charles Voast, tailor, is mentioned in a Will;
he made over his goods to his son Henry in 1689. It is almost certain that
they were related to the first Voste in Ramsey, Richard, a shoemaker,
(c. 1690-1766) who married Jony Cottiman, and who bought "an old house
and garden situated on the hill or knock" (Ballure Road) in 1718. Richard
and Jony had three sons, Henry, Richard, and Charles, who all predeceased
them. Henry was a mariner on a ship belonging to Liverpool, and Charles,
who married Elizabeth Christian (Hall) in 1735, had twin sons John and
Richard in 1736, and died in 1738. Only John (1736-1809), who became a
cooper, survived childhood. He and his wife Mary Douglas sold the original
home on Ballure Road in 1789 and lived in "John Voast's Double Roof
House" on Market Hill. Their eldest son John's son John was a dealer in
Ramsey in 1838: their second son Charles (1770-1853) married Jane Inch, and
became Harbour-Master in 1838, remaining so until his death. His memorial
stone at Maughold bears the inscription:

In memory of
Captn Charles Vaust,
for many years Master of the smack Mona
Castle, trader between the Isle of Man and
Liverpool, and late Harbour Master of
Ramsey, who died
Ist of October, 1853, aged 79 years
This monument was erected as a token of
respect by a few friends
1855.