I did a search but only found a few posts that mentioned Nihau, but no posts from people that have been there.

I'm wondering if anyone has "invited" themselves to this "Forbidden" island?
You can't stay overnight, but you can take a helicopter tour that lands at one of the beaches, or you can go on an expensive game hunting safari. See this link:

Island Info

Haven't been there but have taken a Na Pali coast cruise from Holoholo charters which also has snorkeling trips to Ni'ihau for $169 including breakfast and lunch leaving from Port Allen. Check ebay for possible better deals.

You might have more luck with your search if you spelled it correctly - Ni'ihau - or closer to correctly - Niihau.

Hehe. Actually, I just tried two searches right now with both of those spelling, and I got the same results. I guess no one here has posted any trip reports about this island, or no one here has actually taken the trip (probably the former).

When I go to Kauai eventually, I'll consider taking this sidetrip just so I will have visited all the islands. Right now, I've only been to Oahu, but I'm Maui or the Big Island will probably be next before I go to Kauai.

We did the helicopter thing in August 2004. Only one other couple. On the way over a Niihau resident rode along with us, going home. The pilot and my other half grew up in the same town on Oahu, so they talked story.

At the office where you check in before going to the helicopter they have some amazing Niihau shell necklaces for sale.

When you land there is just a "tin shack" for shade, no other facilities. The helicopter people bring lunch and water for you.

Beachcombing is fun, shells bigger than I've seen on any other Hawaiian beach, and also the teeny Niihau shells, way too small for my eyes and fingers

A monk seal lounged on the beach and in the tidepools the entire time we were there.

The most astounding thing was the amount of rubbish washed up on the sand. Amazing. Rubber slippers, bottles, fishing floats (no glass ones the day we were there), rope, .... Really pretty disgusting.

But, I was able to snag a fairly big (about 12 inches in diameter) black plastic fishing float and take it home. The airline security and baggage people were amused. One of them called it an "orb", so that's its name now.

All-in-all a great experience. You really feel like you're in the middle of nowhere. Thank goodness for the tin shack to take a break from the sun. But what are we going to do about all that trash washing up?

I almost forgot -- making a reservation for the helicopter was an on-and-off affair. If you go, call as soon as you get to Kauai. It took a couple of days to work out the logistics. Since there was only two of us, we either would have to pay for the entire helicopter cost, or hope someone else signed up to split the cost. We were all set, then other people canceled, fortunately, just in time another couple signed up. That was fun too, their english and our japanese were equally bad, so we gestured and pointed

I too have been curious about this little island. Goggle will take you to lots of sites on the history of Ni'ihau. The sense I get is that the locals there would generally prefer to keep the outsiders out.