Why the head is the problem area
Three facts converge on it.
It faces the sky continuously. Sitting, paddling, waiting, turning to look at a set. The top of the head, the tops of the ears and the back of the neck are presented upward for the whole session, in every posture the sport involves.
Nothing covers it by default. The wetsuit stops at the neck for most of the year. In warm water even that is gone. The head is simply out there.
It is where the damage in this sport concentrates. Scalp, ears, back of the neck and lips are the areas a surfer's exposure loads onto, and every one of them is on the head. The whole of the exposed ground section is about this.
Put those together and headwear is the highest value single item in a warm water kit bag, above any top and well above anything applied.
Retention is the entire engineering problem
Ask people why they do not wear something on their head and the answer is not that they think it is unnecessary. It is that it comes off.
A duck dive, a wipeout or a wave on the head will remove anything that is not positively retained, and the sea does not give it back. A cap without a strap is a donation. Any solution that does not solve retention is not a solution.
The categories that exist and what each one does about retention, described functionally because this manual names nothing:
Neoprene hoods. Positive fit, seal at the face, cover the scalp, ears and the back of the neck. Worn for warmth in cold water and they happen to be excellent sun cover. Warm, which is the limitation in summer.
Surf caps and water caps with chin straps. Designed for the purpose, retained by a strap, generally with a peak and often with a neck flap. This is the category built for the problem.
Neoprene beanies. Cover the scalp and often the ears, retained by fit, no peak so no shading of the face.
Ordinary caps. Not retained. Fine for the beach, gone in the water.
Legionnaire style flaps. Address the back of the neck directly, which is the area that matters most, and are found on some water specific designs.
| Category | Retention | Covers | Limitation |
|---|---|---|---|
| Neoprene hood | Positive, seals to the face | Scalp, ears, back of neck, forehead edge | Too warm for summer |
| Neoprene beanie | Fit only, usually reliable | Scalp, often ears | No peak, so no facial shading |
| Water cap with chin strap | Strap | Scalp, often neck flap, sometimes ears | Ear coverage varies, check it |
| Legionnaire style water cap | Strap | Scalp, ears, back of neck | Bulkier, and not universally liked |
| Ordinary cap | None | Scalp and some of the face | Gone on the first duck dive |
| Nothing | Not applicable | Nothing | The default, and the reason this section exists |
Working framework of this manual. It is not a measurement, it is not drawn from any study, and it carries no numbers we cannot source.
What headwear does not solve
Being clear about the limits, because a false sense of coverage is worse than none.
Reflection from below. A peak shades from above. Light bouncing up off the water goes straight under it and reaches the underside of the chin, the nose, the lips and the eye area. See reflection off water.
The face. No headwear covers the middle of your face while you surf. That remains an application problem, described in the face inside a hood.
The ears, unless it actually covers them. Many caps leave the ears fully exposed. Given that the tops of the ears are one of the most reliably affected areas in this sport, that is worth checking rather than assuming. See ears.
Your eyes. Related but separate, and covered in eyewear that stays on.
Hair is not cover, and thinning hair changes the question
A full head of hair provides some physical cover to the scalp, and less than people assume, particularly along a parting where the skin is directly exposed. Wet hair lies flat and separates, which opens partings further.
For anyone with thinning hair, a receding hairline, or a shaved head, the scalp is simply exposed skin at the highest point of the body, facing the sky, for the entire session. That is a different situation from the one most sun advice pictures, and it is one of the strongest arguments for headwear in the sport. It is dealt with directly in the scalp and the parting.
The summer problem
The category that solves retention best is neoprene, and neoprene is warm. In a hot summer session a hood is not appealing and telling people to wear one is not going to work.
Which is why the water cap category matters. Lighter fabric, chin strap, peak, sometimes a neck flap, designed to be worn in warm conditions. It is the answer to the objection rather than a way of ignoring it.
The other summer answer is a cap worn with a strap, or a cap worn under a leash of some description, and it is worth accepting that some people will only ever wear the lightest possible option. A light cap that is actually worn beats a hood that stays in the van, every time. The purpose is not to be maximally covered, it is to be covered at all, repeatedly, for years.
What to take away
The head faces the sky for the whole session, is not covered by anything you already wear once the water warms up, and is where this sport concentrates damage. Headwear is therefore the highest value single addition to a warm water kit bag.
Solve retention first, because an unretained cap is a donation to the sea. Check that it covers the ears and the back of the neck, not just the crown. And choose something light enough that you will wear it in summer, because the version you actually wear is the version that works.