Must take items to Fiji

My wife and I are arriving Treasure Island late June for a "kick back and unwind" style mid year holiday ( 8 nights).
We haven't been to Fiji before and wondered if some experienced travellers could recommend some must take items other than the boardshorts, sunnies and books.

Also we have a full day in Nadi on the way home. Any suggestions for a great way to fill in the day? Any must see places even if we need to hire a car?
If any one has been to Treasure Island I 'd also really appreciate any comments, tips etc

Insect repellent.

I assume "boardshorts, sunnies and books" was not meant to be taken literally as ALL you'll be taking ...

When I was in Fiji I wished I had not taken so many clothes with me since i traveled around. You see, ironically first day after my arrival i realized I should leave a half of my stuff at a hostel in Nadi.

drink (stubby?) coolers and a bottle opener!

Bring your own snorkel and mask if you have them. Other than that, travel light - you really don't need that much in Fiji; as you said, boardies, sunnies and books (and maybe a shirt for night time!!). As for a day trip from Nadi, I recommend going to Lautoka. You can get the bus from just outside the McDonalds in Nadi (ask any local taxi driver if you dont know where it is). Look for any bus heading north, hop on and ask them. Buses were every 30 minutes i think and didn't cost much. Journey was about half an hour. Lautoka is a really nice place, much more genuine than Nadi and one of its big attractions is the indoor market. There is also a rugby stadium and if your lucky there might be a game on. Have fun!

Treasure Island is a great place to "kick back and unwind". If you enjoy eating snacks between meals, then it is worthwhile taking snacks with you as the resort shop at Treasure has limited options that are not cheap. One of my favourite things to do at Treasure is to eat at least one night at the Flambe Restuarant. It costs about $20FD extra per head, but you have a chef who cooks the food at your table with lots of flames.

Another tip for Treasure is to book your dinner table as early as possible. If you don't, you risk having to sit outside and I found last June, it can be brisk if there is a breeze blowing.

If you are at all into sports, then it is good to see the staff play volleyball nightly at 5pm. You can join in, but the staff do play hard.