[alancalverd (OP)]

Waves are caused by the interaction of wind and tide.

Wind direction varies, tides flow in and out.

But the waves always travel towards the beach.

Why?

[Bored chemist]

Because the land stays still and the sea goes up and down.

[evan_au]

Waves are generated in the deep ocean, traveling in all directions (as the wind changes direction).
But you don't see the waves traveling away from your beach - they land on a different beach.

PS: There is one instance where you can see waves traveling away from your beach: Due to the impedance change when striking the beach, some wave energy is reflected out to sea. In shallow water, you can see these outgoing waves collide with incoming waves, producing a splash that jumps skywards. Because the outgoing wave is not exactly parallel to the incoming wave, this spurt often travels at high speed along the wavefront.

[Eternal Student]

Hi.

I'm fairly sure I've seen this question on the forum before.   Still, it's a very lovely question and thank you very much for submitting it.

   Do you know those rocky outcroppings where crabs play in the rock pools?  In fairly quiet seas you can often see some reflected waves coming off those things without much difficulty.   You don't just have little spurts like evan_au was saying.   Anyway, those reflected waves can often be seen clearly moving in the opposite direction (away from the main bit of beach).

   But, on the whole, it's as described already.   The average wave is just moving away from its point of origin and its origin was never on the beach, so the beach is always away from the origin of a wave.

Best Wishes.

[Colin2B]

But the waves always travel towards the beach.

Why?

Refraction
You are right, it doesn’t matter which way waves approach a beach they will always turn in towards it. They usually approach from far offshore as determined by wind direction. As the wavelength approaches water depth the wave front slows and wavelength shortens. Net effect is wavefront closer to beach slows and the front turns towards the beach, usually ends up parallel, but sometimes not quite, depends on underwater topography.
Waves will also refract around islands and underwater sea mounts giving unstable water on the side away from the wind.