I was asked to post pictures of the Gs that I hyro modded, so here goes!
I used 15wt silicone oil that I bought at a local hobby shop. I didn't know it was red until I poured a little into a container. I originally wanted to use clear but this turned out nicely. The red colored display on the 7900 goes really well with the resin in my opinion. The Riseman and In4mation already had red displays and the oil just made them POP more, I really like how they turned out. I saw blue, green, and a few other colored silicone oils so I'm going to pick some different colors up and mod a few other of my Gs.
The Riseman's bubble split into two and they're in different parts of the display now, pretty funny. The In4mation had a bubble but it went behind the module. Hopefully it reappears because I like the way it looks. The digits are also sharper and have more contrast.
Overall the process was so much easier than I had imagined. Two pieces of advice: First is to run the oil through a coffee filter or another type of filter that will clean out small particles. Like most oils I believe the silicone oil is recycled and I noticed tiny black pieces of material, I think maybe metal shavings or something. The other piece of advice is to get the bubble the size that you like and submerge the case in oil so when you reassemble the watch you don't trap more air. If you do it will eventually make its way to the front and you will have a huge bubble...I'm speaking from experience
Added bonus is the weight of the watch! They feel so much more solid. I can only imagine what a Frogman would feel like.
The main reason I did this mod is so I can free-dive to 1000m, my watches weren't able to go that far before.
Let me know what you think!
The Riseman picture is pretty washed out. In person the display is a deeper red.