Luggage and bags:
Waterproof covers for your bags are essential in case you end up sleeping on the lower deck of the boat.
Clothing/Shoes/Weather Gear: Reef shoes or strong trainers if you intend walking in the sea or along the coast.
A waterproof coat in case it rains while on the boat.
Toiletries and Medical Supplies: Sun cream.
Essential or prescription medicines.
Miscellaneous: None of the above is available in Tokelau, so make sure you take them with you.