ship owned by king kamehameha ii , the second king of hawaii , sank off the coast of kauai in april 1824 .
shipwreck chaser richard rogers excavated site between 1995 and 2001 .
retrieved a boat whistle , a ring , utensils and a trumpet shell .
collection had been kept at the smithsonian .
has been delivered to kauai museum and will go on display later this year .