A beach bag gets heavier every year until nobody wants to carry it and half of it comes home unopened. This is the short list — seven things, one tote, packed in five minutes — and the reasoning for each one.
The seven
1 · A real broad-spectrum SPF
SPF 30 for an ordinary day, SPF 50 with a PA rating for the beach itself. This is the item the whole day depends on, so buy the size you will actually use generously rather than the one you will ration. A full-body adult application is around 30 ml — a shot glass — which means a 100 ml bottle is roughly three applications, not a season. Why that matters is in the SPF article.
2 · A tanning oil, if you are tanning
Separate item, separate job. An SPF 2 oil is a conditioning product, not sun protection — it goes on the skin you are deliberately colouring, while the real SPF handles face, ears, chest and shoulders. The method is in how to apply tanning oil.
3 · Aftersun — but leave it in the car
It has no job on the sand. Its job starts in the shower, and it works best on skin that is still damp, so what you want is for it to be waiting where you will be in an hour. Aloe gel kept cool is even better. The full routine: the after sun ritual.
4 · A hat with an actual brim
A broad brim is the WHO's first line of sun protection, ahead of sunscreen, and for good reason — it covers the face, ears and back of the neck all day without being reapplied, sweated off or forgotten. A cap leaves your ears and neck exposed, which is where people most reliably burn.
5 · Sunglasses that block UV
Eyes take UV damage too, and the thin skin around them is among the first to show sun ageing. The WHO specifically recommends sunglasses with side protection. Dark lenses without UV filtering are worse than none — they open your pupils and let more UV in.
6 · A rash guard or a loose long-sleeve shirt
The item people skip and then wish they had. Fabric protects completely, never needs reapplying, and puts nothing in the water — which matters if you are swimming over reef. It is also the easiest way to extend a beach day past the point where your skin has had enough.
7 · Water. More than you think.
Heat, sun and salt water together are properly dehydrating, and skin recovering from UV does not do it well while you are short of fluid. Freeze one bottle the night before and it doubles as the cold thing you press against your neck at two in the afternoon.
What to leave at home
- Last year's sunscreen. Check the date and the period-after-opening symbol. Filters degrade, and a bottle that has spent a season in a hot car is not delivering the number on the label.
- Anything above SPF 50. You are paying for about one extra percentage point of UVB. Buy more SPF 50 instead and apply it properly.
- A second towel "just in case". There is never a case.
- Makeup with a low SPF as your only protection. Nobody applies foundation at 2 mg/cm². It is a bonus, not a layer.
The five-minute version
If you remember one sequence: check the UV index, pack shade before you pack product, then bring the two bottles that do different jobs. Hat and shirt handle the hours; SPF handles the skin you leave out; oil handles the colour. Everything else in the bag is comfort.
Check the sky before you go — there is a live Bangkok UV reading on the Sun School page, and how to read it takes three minutes.