vmg as displayed on the velocitek gps unit is very usufull and as a training aid when sailing alone essential as theres no other way to physically assess your performance on the water , it also clearly tells you what angles pay downwind and wether its worth trapping when solo or sailing deeper , simple speed function is more usefull than you may think too as you can come off the pace without noticing , say a 10% diff when beating at 10 knotts is hard to tell by human analogue , new velocitek gps have twin displays and can also show compass headings too , and at the end of the day its a gadget !!!!

Could be better with integral mp3 player and fek orf speakers <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />