These can be seen by tours from Kuching Sarawak Malaysia. Click here
Dugong are occasionally seen at Mantanani Island. Probably a single individual!
Dugong are very rare all over SE Asia.
Goliath grouper can sometimes be seen on wrecks or under the oil rigs of Brunei and Labuan. The Kuching wrecks and submarine apparently have a few resident individuals. They have been fished out at all known dive sites in Sabah. The only guaranteed place to see is at the Green Connection.
Goliath grouper are protected by International Law but are not protected in Malaysia.
Leopard sharks are large attractive bottom living sharks. They are naturally rare and overfishing has made them virtually extinct in the waters of Sabah.
All sharks suffer from politician and legal indifference. There are more Orang Utans in Borneo than these sharks yet the shark has no protection at all.