Packing for a day or a week on a boat is mostly about restraint. Space is limited, everything gets damp, and the list of things that genuinely matter is short.
The rule about bags
Soft bags only. Hard suitcases do not fit in boat lockers and there is nowhere to store them. Almost every charter operator asks for this, and the ones that do not still mean it.
Sun, which is the main hazard
Hawaii’s sun is stronger than most visitors expect, and on the water it comes at you twice — directly and off the surface.
Long-sleeved rash guards do more than sunscreen, do not wash off, and are what experienced crew wear.
A hat with a brim and a strap. The strap is not optional; a hat without one is a hat you will watch float away.
Sunglasses with a retainer, polarised for glare.
Reef-safe sunscreen, which is required in Hawaii, and more than you think.
Clothing
Quick-drying everything. Cotton stays wet and gets cold once the sun drops.
A light windproof layer — it is cooler on the water than ashore, especially heading into the wind.
Swimwear you can wear all day, and one dry set of clothes kept in a sealed bag for the trip home.
Deck shoes or bare feet. Not black-soled shoes, which mark the deck, and not new white trainers you care about.
The things people forget
Seasickness medication, taken before departure. Once you feel unwell it is largely too late. Take it an hour before, even if you think you are fine.
A dry bag for phone, keys and camera. Spray reaches everywhere.
Motion-tolerant snacks. Something plain and salty.
A towel, if not provided.
Cash for tipping the crew, which is customary.
What to leave behind
Hard luggage. Anything valuable you would mind losing overboard. Excess clothing — you will wear the same two things. Full-size toiletries. Heels.
For an overnight or longer
Add a headtorch, a warm layer for night watches, and any medication in original packaging.
And ask the operator what is actually aboard before duplicating it. Most charters provide towels, snorkel gear and basic supplies, and bringing your own uses space that does not exist.
