Travel Considerations

My best friend is 87 y.o. He wants me to do a cruise with him on a 160 passenger ship to Antartica. I have been diagnosed with MG since last October, and am stabilized with mestinon and gabapentin. I haven't had any flare ups or crises. My only symptoms are leg cramps and muscle weakness. I have evacuation insurance, but would it be safe to take this trip? I think it is my last with my friend due to his age and health.