I have the ICOM. I always use an Aquapac, even on this floating, watertight etc etc. Not only does it keep water out but it eliminates all wind noise when speaking. This has become recommended practice here in Dublin Bay following an incident when communication was difficult because of wind noise.
I attach radio by a cord. I pass my left arm through large loop at end of cord, which is then is passed behind neck. Radio then hangs over my right shoulder. This means I can hear it, operate it with left hand while steering, and VHF stays in place and doesn’t get in way. I always attach radio before putting on lifejacket.