These pesky little dots are known as Lens Flare and happen sometimes due to reflection inside the lens itself or even tiny dust/sandparticles on your lens. Try giving it a wipe with a lens tissue next time :)
In this photo I would say it is a reflection - see how the flare is looking like / almost copying a pattern of the sun itself?
Take a couple steps back and focus towards the horizon of the water and see how you go. Good luck!
