In Transformers (2007) Captain Witwicky is venturing about the Antarctic. I believe he states he's heading to the Antarctic Circle? On this voyage he stumbles upon Megatron frozen below the ice, but this was not the voyage goal. Why was he exploring the Antarctic to begin with?
Based on his lines in the movie, "That be the smell of treasure, lads.", he was leading an expedition to the arctic circle to look for fame and/or riches. That statement probably shouldn't be taken literal. Treasure probably means "what we've been looking for" which is probably anything scientifically significant which is why expeditions to exotic/remote places take place.
Another statement he made was, "We'll get to the Arctic first, lads! No sacrifice, no victory!" which also suggest a scientific expedition.
Some sources say he wasn't a real captin which would suggest he was leading a scientific expedition instead of a military mission. I'm looking for a solid reference to confirm this.