My tablet has Navionics HD which is different to the basic version on my phone.
On the tablet when plotting a new route, there is supposed to be a "remove last" function for deleting the last way point entered.
I can't see how to do this. It should appear when new waypoints are being added. I've searched all the usual places for info - Google, You Tube etc to no avail.
Holding a finger on any waypoint allows it to be moved but I still can't see how to delete the last one.
Pressing "cancel" deletes the whole route.
On the basic version on my phone there is an "undo" button which is easy enough.
I tried to get a screenshot also but can't figure that out either. The camera icon on the screen switches on the camera in the tablet.
Can someone please put me out of my misery?
I think all you have to do it tap (touch it for a short time) the way point and a menu appears. If you hold it longer then it allows you to move the waypoint. 
Thanks Crusoe. Tapping worked.
I followed the instructions in the help menu.
It says Click the "Remove Last" button, which appears when waypoints are being added, so I assumed it meant leave the finger on instead of a tap.
There is no "remove last" button.
Anyway - all good!
