Ko Kham (Thai: เกาะขาม) is a small island near Ko Mak, on Trat Province, Thailand.
It can be reached with a sea kayak from Ko Mak or by walking during low tide. Ko Kham has nice places to snorkel, depending on the direction of wind. Especially the south beach has a calm sea, nice sand dune, black lava rocks with shells and crabs (or crayfishes or shellfishes). Near rocks, you may see (or swim over) black sea urchins that have 15-30 cm radius and many thin black spines about 30-50 cm long. Locals say that the spines contain small needles and poison: if one touches the spines and gets the needles, the needle should be crushed with a rock. The poison is only irritating and not lethal. In Thai, the name is Hoi Ment (หอยเม่น).