After many hours flying floats and a tad over 3000 water landings, (in my case), I'd say you get to read the water perhaps a bit like a black-tracker sees indicators invisible to city-slicker eyes. There can be a world of difference between looking and seeing.
Until you get your eye in , so to speak, it's best to never rush it. If the sun is out it's simpler. Just orbit once or twice sussing out your chosen alighting path. Any wind over ten knots means you'll be seeing wind lanes, sometimes subtle, sometimes as plain as any discharging smoke-stack.
As the late Fred 'A Shower of Spray and We're Away' Ladd used to say, a seaplane pilot can have more fun on and off the water than in and out of bed.