I shoot with the Nikon D7200 also and I use the Nikon 60 mm 2.8 micro for macro and fish photography. Since you are using it on a crop sensor it ends up being closer to a 90mm. I have not tried it but I understand one of its draw backs is for super macro as it would be very difficult to use multipliers since its focus distance is so close. It is an amazing lens and great autofocus for macro, with most photos at tack sharp. Ive used it from the tiniest Shaun the sheep nudibranch to great fish portraits. Below are a couple of samples, check out my flickr for more.
You can also use the Nikon 105mm, which with a crop lens would be like using a multiplier for supermacro. I have it but have not used it underwater. My understanding is that you have to use the manual focus mostly.