We have a cruise from Lisbon to M/C. Looking at air fares, it seems round trip Bos/Lis is easily the most practical. So what do you recommend for getting from MC back to Lis. Train?

If you have not purchased your tickets yet, look for an open jaw ticket: Boston to Lisbon and Nice to Boston. If you insist on going back to Lisbon, look for air fares from Nice to Lisbon.

If you must go back to Lisbon - TAP flies nonstop from Nice to Lisbon. Train is not really an option.
But Michael's advice is the best - check if you can fly to LIS and back from NCE.

Thanks, don't have to return LIS. Never heard of open jaw-that a brit term?

Open jaw (or multi-city flights on most air websites) usually cost a little more. I checked one period in June and it was about $100-120 more to fly in to Lisbon and out of Nice, for example. A lot better than backtracking, at least in this case. Does your cruise line offer air fares? We have done really well with them in the past (especially transatlantic because they have fabulous one-way rates), and our son found a Delta One ticket that wasn't much more than Economy on a recent European cruise. Either way, the French Riviera is fantastic; hope you have some extra time to enjoy.