Thank you. The physical properties of light are constant and they are, luminance (brightness), hue (color) and direction. The size of a light source and the distance from the subject will create either softness or harsh shadows but most of these factors chance when using lasers. The luminance and color change little so direction is the pretty much were creativity appears.
Water is only slightly less inert than air so to see the lasers effect you need dirty air or dirty water. You can use water to create a wave frequency to reflect the laser off of but even the altered reflection creates a small intense spot above the wave and a similar but more spread out caustic effect under the water. I've learned it's more effective to alter the surface being illuminated is then what it reflects off.
Try some things and ask any questions you'd like.
