Keith Reynolds the designer of the stamp gives; September 1797 the crew of the BRITANNIA sighted Alinglapalap and Kili of the Marshall Islands on a voyage to China.
At that time there were a few ships under the name BRITANNIA in this part of the world, but the book Foreign Ships in Micronesia gives:
British merchantman BRITANNIA, Capt. Thomas Dennet, on voyage to China, Sept. 19: Sighted “Hunter Island” or Kili. Eight canoes came off with natives who wanted to trade breadfruit. Sept. 20: Sighted “Lamber Island” or Ailinglapalen. Several canoes headed for the ship and natives were eager to trade. The ship did not stop, however. Sighted “Ross Island” or Namu the same day. Several natives came out while the ship stood off for a short time.
Traded mats and skirts for iron hoop. Natives tried to knock off ruder chains and one tore off a gallery rail. Sept. 21: Sighted “Princess Island” at 08 21N 167 25E.
I got a BRITANNIA in the convict trade, captain name Thomas Dennott, which arrived in Australia on 27 May 1797. The surname of the captain is not exact the same, but in that time many names were given different in sources. Anyhow this BRITANNIA was at that time in the Pacific and the other BRITANNIA’s were on an earlier or later date in the Marshall Islands.
She was built in 1774 at the Bombay Dockyard for Waters & Co. Ship rigged, with a tonnage of 500 tons.
What she was doing between 1774 and 1795 is not clear, but most probably used by the East India Company
Lloyds Register gives then:
1795 Sailed from London to India.
15 May 1796 under command of Capt. Thomas Dennet arrived at Plymouth from Bengal, sailed for London.
01 Sept. 1796 sailed from London for Cork. 10 Dec. 1796 sailed from Cork for Botany Bay with convicts.
Bateson in his book “Convict Ships 1788-1868” gives, the voyage of the BRITANNIA was one of the worst in the history of convict transportation to Australia, and the captain was a sadist.
When the BRITANNIA sailed from Ireland on 10 December 1796 with on board 144 male and 44 female convicts, captain Dennott’s orders to the mate, John Thomas Ricketts were very harsh. They (convicts) were never allowed on deck in batches of more than 30, and no longer than for 2 hours, and when on deck were chained to the shipside. The irons had to be inspected twice a day.
When a convict had to be punished so many lashes were given by the cat with nine tails, that the convict died mostly on his wounds.
When a supposed mutiny was discovered, one man first received 300 lashes and the next day 500, others were also flogged twice with more as 300 lashes.
When the BRITANNIA arrived in Sydney on 27 May 1797, ten male convicts and one female had died during the voyage, mostly after the harsh flogging ordered by Captain Dennott. A inquire was ordered by Governor Hunter, the court was unanimous that the treatment of the convicts had been imprudent, and that the surgeon Augustus Jacob Beyer and Captain Dennott were to blame, at least the captain should have been convicted for manslaughter, if not of murder but neither Dennott or Beyer were punished, except that both men not again were employed in the convict trade.
The BRITANNIA sailed on 02 August 1797 from Sydney for China for a cargo of tea; most of the ships used in the convict trade were used for whaling after disembarking her human cargo, or chartered for a return voyage from China by the British East India Co.
Lloyds Register gives then:
07 Feb. 1799 arrived under command of Capt. Thomas Dennett at London from China.
L.R. 1800 gives her owner as Lambert and the Capt. as Palmer.
28 May 1799 sailed from London for Madras. 30 Sept. 1800 arrived at London from Bengal.
L.R. 1801 gives her owner as Cleland and Capt. as Johnson.
21 Jan. 1801 sailed from London for Madeira and India. In Portsmouth her captain was relieved by Capt. Stout. 31 May 1802 arrived at London from Bengal.
06 Sept. 1802 under command of Capt. Reddie sailed from the Thames for Bombay, arrived Nov. 1802 at Teneriffe. Thereafter not any report found in L.R. Mr Benn checked L.R. till 31 Dec. 1804. Most probably used solely in the Indian coastal trade.
Marshall Islands 1992 15c sg 487. scott 443.1994 15c sg MS549, scott 466Cd. 1992 32c sg 669, scott 605a
Sources: the books mentioned in the text. Info received from Mr. Benn.