On the recommendation of a veteran dive photographer, I tried making my own arm foats for my Ikelite strobe arms out of pool Noodles. The Noodle floats gave me some bouyancy on the surface, but lost bouyancy when I dropped under the surface. I'm sure pressure put the squeeze on my homemade floats.
I shoot with twin Ikelite DS-161 strobes and the 161's are heavy. I switched to using Stix floats. The Stix products work well. I use float arms and a modified Stix float strap which fits around the extension for my flat port. I beveled the edges of the floats on the strap to make it fit angles on the port extension. I space the floats on the strap so there are two floats between each of the extension lock buttons on my Ikelite housing.
The only downside to my arm/float setup is that I need switch to longer strobe arms. The length of my current strobe arms is not long enough to work well with my wide angle lens.
One of the best mods I made to the Ikelite housing/strobe arm rig was to make a strap system which would allow me to attach the camera housing to the D-rings on my BCD. My BCD carries the weight of the system rather than my arms and hands. It works well for beach diving and is easy to clip into when the camera rig is passed down to me after I make entries during boat dives. I don't have to wrestle the camera rig when making surface swims.