Gordian III, AE27 of Amastris, Paphlagonia. 

Obv: ..VT GORDIANOC AVG, laureate, draped, cuirassed bust right
Rev: AMACTR(IANWN), Isis Pharia sailing right, head facing, 
holding a billowing sail. 

Not in SNG Cop, BMC, Mionnet, Isegrim database, Lindgren. 

With permission of Roma Numismatics (item 8767, hence the reference), Jun, 2010