I guess converting bat fish photos to a monochrome is quite common to show the stripe pattern of bat fish.
Since we can't preview the results of software editing underwater, how do you make sure conversion can be satisfied?
Any ideas to prove my pictures?
You can't do post processing in the camera but you can set your camera to display the results of your photo in B&W rather than color if that is what you are trying to do.
I might try over exposing one to two thirds of a stop to get good highlights and then pull out the shadows more in post to get a strong contrast with less noise. Don't shoot monochrome on a DSLR, convert it. Oh, and learn to imagine things in black and white!