Come and ask, answer or inform.
| Date from | Date to | Event | Source |
|---|---|---|---|
| 2.5.1732 | 4.6.1734 | Tiger (50), Volunteer-per-order ADM 6/14/106 | ADM 6/14 |
| 4.6.1734 | 17.8.1738 | Roebuck (40), Volunteer-per-order ADM 107/3/397 | ADM107/3 |
| 27.11.1740 | Passed the Lieutenant's Examination | RNLPC | |
| 2.2.1740/41 | Lieutenant ADM 6/15/375 | CSORN | |
| 11.3.1748/49 | 24.1.1750/51 | Mercury (20), Lieutenant ADM 6/17/447 | ADM 6/17 |
| 17.2.1755 | Commander ADM 6/18/349 | CSORN | |
| 17.2.1755 | 4.7.1755 | Kingfisher (14), Commander and Commanding Officer ADM 6/18/349 Issued by Charles Watson (1714-1757) Commission confirmed 27.1.1757 | BWAS-1714 |
| 4.7.1755 | Captain ADM 6/19/132 | CSORN | |
| 4.7.1755 | 2.3.1758 | Cumberland (66), Captain and Commanding Officer ADM 6/19/132 Issued by Charles Watson (1714-1757) Commission confirmed 29.1.1760 | BWAS-1714 |
| 11.1.1756 | 14.1.1756 | Capture of Geriah | |
| 2.3.1758 | 11.2.1762 | Yarmouth (64), Captain and Commanding Officer ADM 6/19/292 Issued by George Pocock (1705/6-1792), East Indies Commission confirmed 16.3.1760 | BWAS-1714 |
| 29.4.1758 | Battle of Cuddalore | ||
| 3.8.1758 | Battle of Negapatam | ||
| 10.9.1759 | Battle of Pondicherry | ||
| 11.2.1762 | 24.2.1763 | Namur (90), Captain and Commanding Officer ADM 6/19/385 | BWAS-1714 |
| 6.6.1762 | 13.8.1762 | Operations against Havanna | |
| 1763 | Suffered a Stroke of the Palsy from which he never fully recovered and held no further commands as a result | B051 | |
| 1.1.1779 | 27.3.1779 | Included in the list of captains receiving half-pay. | ADM104 |
| 27.3.1779 | Superannuated Rear-Admiral ADM 6/21/533 | ADM104 |
He was Buried in Westminster Abbey, where his memorial monument reads:
Near, lies buried rear-admiral JOHN HARRISON, son of captain Robert Harrison, who educated him from his infancy in the navy, having himself served in it forty years. He was captain of the Namur, the ship of admiral sir George Pocock in several successful engagements with the French fleet, commanded by the count D'Ache in one of which he was wounded. He conducted under the same British admiral, the armament against the Havannah, and brought the fleet and treasure safe to England. In consequence of excessive fatigue, soon after his return he lost the use of one side by a paralytic stroke, and remained helpless twenty-eight years. He was firm in action, prudent in conduct, polished in society, generous and humane. in a profession, and upon an element where human virtue is of the most rigid kind, and human nature is nost severely tried, his modesty was equal to his virtues.