Yeah I agree with the cable and keep one on the boat.
You can also ring up to log in. Last time I radioed in I was on the other side of the headland and I got no response. I figured I'd radio one again when I moved out but the marine rescue guys heard the boat name and called my mobile.
I also have the local marine rescue bases, fisheries and the like in my phone contacts. I generally add extra words so it's more likely to come up if I have a mental blank and use the search function.