Captain Thomas Thomas Howe

Thomas, commanded  a ship (perhaps a small fleet)  for the East India Company,  1762–4 and 1766 to South Asia.   He and made observations on Madeira  and on the Comoro Islands, an archipelago off of the S.E. Coast of Africa. Possible candidate vessel  under his command was the EIC ship   Royal Charlotte (1761)  which made three trips to India and the Red Sea for the EIC between February 1762 and July 1770.  (Wikipedia source says his EIC ships were the Winchelsea and the Nottingham, but these craft came  into service  after his death.)

Thomas was also a chart-maker as evidenced by a group of important charts of the Maylay Archipelago, printed on 15 separate sheets, which were produced between September 1804 and May 1805 by the East India Company Hydrographer Alexander Dalrymple, as an accompaniment to his Memoir of a chart of the passages at the southern extremity of Asia whose title is "Sketch of the Straits of Singapore by The Hon'ble Thomas Howe April 1758"

Source: Memoir of a Chart of the N.W. Coast of Madagascar by Capt. David Inverarity and Source: Madeira. [Memoir of a chart of the N W coast of Madagascar / by Capt. David Inverarity, 1803 ; and Comoro Islands, by the Hon: Thomas Howe, 1766 ; published at the charge of the East India Company, by Dalrymple. 1806

Thomas' mother , Charlotte, the daughter of Sophia von Kielmansegg, Countess of Leinster and Darlington is an acknowledged illegitimate half-sister of England's King George I (U.S. Declaration of Independence Fame)