Goniodoris cf. violacea per https://seaslugcensus.weebly.com/f---h.html
A beautiful but tiny guy. In Jervis Bay off Pinnacle Cave at about 25m. Size was only about 1mm long. After lots of research and chatting to our local dive mates we think it may be ‘Goniodoris cf violacea’ but keen to hear what others think!