Conversation so far:
When was William Dampier's first circumnavigation?
In 1679, William Dampier joined the crew of the buccaneer Captain Bartholomew Sharp on the Spanish Main of Central America. This led to his first circumnavigation.
What was William Dampier's position?
Crew of the buccaneer Captain Bartholomew Sharp.
What happened during William Dampier's first trip?
William Dampier accompanied a raid across the Isthmus of Darién in Panama and took part in the capture of Spanish ships on the Pacific coast of that isthmus.

Question: Why did they circumnavigate?
Self-contained rewrite: Why did the crew of Captain Bartholomew Sharp, including William Dampier, circumnavigate?