Chinaman's Hat, also known as Mokolii Island, is located near Kualoa Ranch about 12 miles South of Laie on the windward side.
Once you pass the entrance to Kualoa ranch the road curves right. Take then next left into Kualoa Regional Park which is 11.4 miles from PCC in Laie.
(See the arial photograph below if you need to get a feel of the location). Chinaman's Hat island will be in view to the left. You can drive to the end of the
As you can see in the photograph below, the coral extends from the beach to the island, and unless there is some serious wheather disturbance, or high tide, the island can be reach by foot (usually not more the waist deep).
Of course you will need an old pair of shoes or strap-on sandals to wear so your feet don't get torn up on the sharp coral. Swimming is another option, but you will still need footwear to use if you want to hike on the island
You will find a small sandy beach as you reach the island and a trail that ascends to the top from the right side of the hat. Be prepared to climb as the summit of the island is a bit steep and requires a bit of bouldering.