The date I read most recently for Thera was 1626 BC. My suggestion that in 100 to 200 years, the remaining ships would be gone, and few rebuilt fits within the time frame to final collapse, which was probably caused by an invasion by mainland Myceneans. Regarding the date 1500 BC, there was a major eruption of Mt. Etna listed as 1500 BC, + - 50 years. I don’t know if there is more recent info on the actual date, but I have always wondered what impact that eruption might have had in the region.
The update is, there was no eruption of Thera, apart from the attested one circa 200 BC. There wasn’t a tsunami. Even the caldera seen today was there for tens of thousands of years. It is strange to me how this has persisted. Zangger notes that the first suggestion of such a culture-shifting eruption apparently comes from late in the 19th c (Evans didn’t start excavation until 1900). It was picked up on in the 1930s (when the Atlantis connection was added, if memory serves), revived again in the 1960s, and periodically ever since (generally equated with Atlantis).