Gonna try your mod soon
One thing coming to mind though, watching your video of use, is it might not be that easy to count the RPM for 1 minute...!
Will have to get used io the right loop moment to count one revolution.
And boat must be of course identified before the use of chart...
Maybe we can have an idea of its speed, even if not already ifentified?
Meaning slow RPM should be obviously slow speed!...and inverse.