How did John Marshall and Thomas Gilbert contribute to the exploration of the Marshall Islands?

In 1788, British naval captains John Marshall and Thomas Gilbert conducted a partial exploration of the islands that now bear the name of the former. While their expedition contributed to the early European contact with the region, they did not perform comprehensive mapping of the area. Much of the subsequent detailed mapping was carried out by later Russian expeditions, specifically those led by Adam Johann Krusenstern in 1803 and Otto von Kotzebue in 1815 and 1823.12