Please can anyone help me trace the FORREST ancestry in the Isle of Mann?

When I cross referenced the surname Forrest with the island, it seems that the first Forrests references to Forrests occured in the first half of the 1800s. It seems to be a group of 3 that started the Forrest line here: Haughton Forrest, William Forrest and James Forrest.

All would appear to have been born around the same time (around 1820s) and so could they have been brothers?

Here is the information I have on them:

1) HAUGHTON FORREST, according to the IGI had two sons: Lowther Somerville Boyes Forrest, born 20 Oct. 1859, baptised 15 Jan. 1860, St. Matthew's, Douglas ; and Edmund Phillip Forrest, born 9 Aug. 1861, baptised 6 Sept. 1861.

The only HAUGHTON FORREST I could find on the IGI was baptised 24 March 1827, British Chapel, Boulogne-sur-mer, Pas-de-Calais. Son of THOMAS Forrest and Mary.

2) WILLIAM FORREST married Cathne (sp.)Cretney, 24 March 1838, Braddan.

3) JAMES FORREST (my ancestor) married Isabella Craine, 7 Jan. 1847, Braddan. In the 1861 census, he and Isabella were living with there family in Liverpool. He is given as being a marine engineer and was born around 1822. It is written he was born in Scotland, but I don't know if this is accurate.

In the 1881 census, (at least) 2 of James' sons were living on the Isle of Mann; Robert Forrest (then aged 16) was living with Annie Craine (his aunt), at 54 Bucks Rd, Onchan. He was an Ironmonger's Apprentice.

Francis William Forrest was 24 in 1881. He was a builders merchant and builder employing 9 men and 3 lads. He and his wife Margaret Elizabeth (Corrin) lived at 19 Brisbane St., Douglas.

So, WHERE DID THE FORRESTS COME FROM?? Who were there forebears?

Any information at all would be greatly appreciated.

Many Thanks, Anthony.