No you dont need a vhf radio,,,,, I do tidal Trent a LOT , is handy if you do have one (you need a lic in theory) a mobile phone will suffice the only place you need 2 persons on board is if you go through ocean lock in Goole and that route is not advisable if you havent done it before , there is the occasional big boat moving up/down river so just keep an eye over your shoulder lockies will tell you if any are on the move ,,pps Thames is a gentle stream compared to the trent in full flow