Here you are Shkval ,
you must place the red marked point to the green marked point (look at pic)...etc
for the tool that pisces is talking you about ,''
there really is no reason to'' use it once you ''
know how'' to do your drawings on navmap .
the tool is not there for ''
helping you to verify the correctnes of your drawing up to this point'' , navmap drawings are as much accurate as accurate your bearing readings are .
so, in case you are wondering why the tool is there then ,the answer is : alternative playing styles ...nothing more and nothing less than this,you choose what suits best for you.