Thanks, RenflowerGrapx.

It's pretty easy. It's just a gradient map adjustment layer over top of the texture converted to black and white and tweaked a bit for contrast, then a few other layers to adjust the lighting some more: a darker ocean, a glow around the shoreline, a texture overlay, a hue/luminosity/saturation adjustment layer...

The basic of it is that I have a gradient layer set up like this, and you can put that on any black and white texture appropriately height-map looking too...

gruberun gradient.jpg

Here it is on another texture so you can see what it looks like when you only have the gradient without the various lighting and texture add ons.
24basemap.jpg

This is what it looks like without the gradient map layer, so you can see where I've added my own touches to get to that result.
alexgruberunsplash-minus gradient.jpg