I'm just looking at the latest version of the publication "The Good Launch Guide". The only launch sites listed either side of Newquay are Portreath and Padstow! I can provide you with further information ref these two sites if you wish? Some years ago my wife & I had a 13 foot V-Hull speed boat with a 30hp engine, all on a steel trailer. Trying to launch at Newquay at low water was a non-starter with the trailer wheels quickly sinking into soft sand. We were staying at Crantock and found the drive across to Falmouth well worth the trip with excellent launching/recovery facilities at any state of the tide! With easy access to the open sea, the River Fal and St Mawes; it's an excellent place to launch.