Scientists, aboard the CSIRO research vessel (RV) Investigator, have explored the deep-sea and ocean abyss, discovering amazing and unique creatures of the deep. The Royal Australian Mint celebrates these journeys of scientific endeavour, and the wondrous creatures they discovered with this 2023 Mintmark and Privy Mark Four-Coin Set.

The reverse of the coins shows the CSIRO research vessel (RV) Investigator and its deep tow camera, as well as brittle star (Ophiuroidea), gold coral (Chrysogorgia), and spiny king crab (Neolithodes flindersi).  While the presentation carton depicts the iconic and elegant tripodfish (Bathypterois grallator).