RN
Every piece of metadata attached to a scene was typed by someone with a reason to type it. Studios tag for search traffic. Uploaders tag to get views. Neither of them is thinking about geography, and that is why location tags are the worst-maintained field in adult video.
Which is inconvenient, because a whole set of preferences are defined by location and by nothing else. If what you want is sand, water and open sky, the thing that defines it is the one thing the taxonomy does not track.
What the tag actually returns
Search any tube for this setting and the results divide roughly into four piles.
The genuine article: shot outdoors, on a coast, in daylight. Usually the minority.
The adjacent-water pile: pools, lakesides, hotel terraces, boats. Tagged in because the tagger was working from vibe rather than location, and because "poolside" has less search volume so nobody uses it.
The backdrop pile: filmed indoors or on a set, with the location doing nothing except appearing through a window or on a mural. This one is large, and it is large because the tag is worth adding whether or not it is true.
The bikini pile: no beach at all, one item of swimwear, tagged anyway.
No amount of refining the search query fixes that, because the problem is not your query. The problem is that the field is unpoliced and there is a traffic incentive to fill it wrongly.
Three approaches that work better
Search the series, not the setting. Studios that shoot outdoors do it in runs. A production travelling somewhere warm shoots a quarter's worth of material in a week, and it goes out under one series name. Find one scene you like, find what series it belonged to, then work through the series. You will get thirty accurately located scenes instead of three hundred guesses.
Search the scenario instead. Much of what people mean by this setting is not really about sand — it is about being outdoors and potentially observed. That has its own vocabulary (public, outdoor, exhibitionist, voyeur) which is far better maintained, because it describes a category of appeal rather than a fact about the shoot, and taggers are consistently better at the former.
Search by production, not by platform. Amateur couples who film outdoors tend to keep doing it and tend to say where. A creator's own upload history is an accurate location index maintained for free by the only person with first-hand knowledge.
The common thread: stop asking the index a question it does not have an answer to, and ask a question it does.
The reason nobody fixes this
Location tagging would need someone to watch the scene and know the place. Sites index at a scale where that is not happening, and there is no revenue attached to being right about it — a mistagged scene that gets clicks performs identically to a correctly tagged one that gets the same clicks.
This is not a defect specific to one site or one niche. It is what happens to any metadata field that costs something to fill in accurately and nothing to fill in wrongly, and it is worth generalising: the tags that describe what happens are usually decent, and the tags that describe circumstances around the filming are usually not.
If it is the production side that interests you
The logistics of shooting adult material outdoors — permits, light, crew size, and why the scenes that look most spontaneous took the most arranging — is a separate subject, and this directory covers it in a piece on how outdoor scenes get made. It is the better read if the question you actually have is why these scenes look the way they do rather than where to find more of them.
For finding more of them, the free tube, amateur and voyeur sections are the three that repay a location-shaped search, in that order.