About the Design:

Obverse
Effigy of king Tupou VI facing, date below

Lettering:
TUPOU VI
TONGA 2015

Reverse
Features the Kalia, a voyaging canoe unique to Tonga. The
shape of its double hulls and large sail enables the Kalia to reach great speed on the open seas. Historically, the kalia was used for navigating the open seas but islanders now adapt it to transport people, food, livestock and crop materials.

Lettering:
KALIA
20 SENITI

Composition    Nickel plated steel
Weight            3.64 g
Diameter    21 mm
Thickness    1.56 mm
Shape            Round