This little flatworm  (30 mm max) was found in about 3 metres (10 ft) of water in the surge zone at Five Graves, Makena, Maui.  At present, I can find no reference to previous sightings in Hawaii, but in their book “Marine Flatworms, The World of Polyclads” Newman and Cannon identify a very similar one from Columbia, South America.  It may well be an introduced Boninia divae (all the way from?) or a whole new species. For now I am listing it as Boninia sp.?  Note:  I found another one of these worms on February 24, 2023 about 1 km away from where I found the first animal in March 2020.  Another has recently been found in New Caledonia.  For more information, see https://www2.sci.hokudai.ac.jp/faculty/en/research-news/8928