Before coming to Hilo I checked out Noonsite, and found this advice:

http://www.noonsite.com/Members/sue/R2012-05-18-2

I can confirm that it is still correct. Radio Bay was pleasant enough five years ago, but is unpleasant and inconvenient now. I anchored off the black sand beach and public park, where there are half a dozen active outrigger canoe clubs, walked along to the Customs office (where I received the same pleasant, courteous service as last time), then thought I 'd better go to the port office. To do that, I had to show my passport, and be checked in and out of the port area. The level of security has been significantly increased, to the extent that it would be very inconvenient to stay in Radio Bay. They told me that only Radio Bay and Reeds Bay were within their control, and no-one is showing any official interest in me at anchor off the beach.
Land on a small beach just to the east of a groyne and the port hand mark for entry into the Wailua small boat harbor (no chance of a berth there, the waiting list is long) - that is where locals bring their small craft for launching. The anchorage is comfortable except when the NE Trades are strong, the holding is good, and the walk into Hilo is about 1 mile. There are toilet blocks in the park, with water supply, cold showers and rubbish disposal.