A couple of years ago I had the opportunity to commission a boat in St. Augustine Florida and then sail it down to Puerto Rico together with three other guys which had done it before. I remember them talking about this green flash appearing in the horizon just as the sun went down. Our trip lasted almost 9 days and I spent every single day staring at the horizon to hopefully get a glance at it. On like the 5th day I did, definitely felt kinda "magical" to experience that. After the sun went down, the nights that we had a clear sky we'd also be treated pretty great. Being on 43 feet sailboat for 9 days with nothing in sight but water and the occasional pod of dolphins is something not many people will ever experience, feel very fortunate.