If John Taggart’s father was the William Taggart who was buried in Braddan in 1843, then this might be him in 1841:

1841
Mucklesgate, Douglas

William Taggert 69 Independent b IOM
Catherine 51 (or 57) b IOM

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After Isabel Taggart nee Christian died in 1820, this could be a second marriage for William:

Event Type Marriage
Event Date10 Nov 1824
Name William Taggart
Male
Marital Status Widowed
Spouse's Name Catharine Giles
Spouse Female
Spouse's Marital Status Widowed
Marriage Place Braddan, Isle of Man

Both signed with an x-mark.
Witnesses Wm Kennaugh and Wm Joughin.
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Have you seen the Masters Certificate of Service dated 4th Feb 1851 of a John Taggart “born Whitehaven, Cumberland in 1803” “employed in the capacities of app mate and Master 35 yrs in the British Merchant Service in the Coasting and Foreign Trades”. Is this your John Taggart, and they’ve got the wrong birthplace ?
Jean