If Gandhi had done map trading he would know the full FC of the other civs cities. So we can safely conclude that he hasn't done that.
Yes, so Gandhi's map comes from his own exploration.
I notice that Gandhi's clam hasn't been improved. Is it likely that he would send a wb exploring if there was the possibility of creating fishing nets? Don't know for sure, but this may indicate that he hasn't got any wb.
Then it might be a galley or another caravel. But I wouldn't rule out the AI building an exploratory workboat before hooking a resource.
Maybe Gandhi is just doing some random exploration with his caravel - I doubt that the AI knows how to get fast circumnavigation.
The exploration pattern is consistent with a boat that was sticking to the coast. If it were the same caravel that did that exploration, it would have had to stick to the coast for three turns, then turn around and retrace its steps back to Delhi, and then head due north. Moving diagonally would have uncovered more fog and been a shorter path around the continent. Why would he intentionally avoid uncovering more fog and saving turns? The timing doesn't work out either. There's not enough time for him to build a caravel, send it west for 3 turns, then east for 3 turns, then north, and then east again.
A second boat makes a lot more sense.
What evidence is there suggesting that Gandhi's caravel is headed east now? If we know this for sure it probably makes most sense to go west and keep map trading with Gandhi hoping that he will waste some turns so that we can get to the western fog line before he reaches it from the other side. And send a work boat to meet the Americans and do some scouting in general.
I bought Gandhi's map 1 turn after spotting the caravel, and he had uncovered tiles consistent with moving the caravel east 3 tiles. I bought his map 3 turns later, and he had uncovered tiles consistent with moving due east. I think it's pretty clear that Gandhi is trying to circumnavigate.
I notice that there's no quick path for a wb to reach the Americans - something like 8-9 turns. It would be much faster to use the caravel. Gandhi will probably have circumnavigated before the wb can contact the Americans.
Given that Gandhi has another boat heading west, it is highly likely that he will circumnavigate before our caravel could reach the western fog line (which isn't static for him). I still think quick contact with the Americans, Chinese, and English is the way to go.