There are times when the conditions are right and the territory is welcoming that it is possible to see several of these White-Margined Nudibranchs in one day.  Despite their commonality, there is something sweet about this caramel-coloured critter that pleases every time.  They are generally around 25mm or 1″ but I can attest to seeing some larger individuals.  All of these animals were found in rocky, relatively exposed areas from Makena to Ma’alaea, Maui.  See the Yellow-margin Nudibranch if you are somewhat confused about the identification and the individual seems lighter and smaller than the average rufomarginata. They are sometimes difficult to tell apart from a distance.  But the White-margin often has a beautiful pattern on its mantle and very obvious brown and white gills and rhinophores.