Cover Board Joint

Like many of my fellow builders there are certain joints on the boat that will be seen by all and inspected.  These include the joints on the cover boards. Cover boards run the length of the outside edge of the deck from bow to stern.  Since there exists amply curve down the side of the boat, we must use 2-3 wide boards and cut them to match the curves.  There are many styles of joints.  Some builders simply make a straight joint.  Others create a elongated S joint.   I did neither.  I created a squared Z joint.  I did this for 2 reasons.  I wanted to maximize the surface area between of the joint for a glue bond.   But more importantly I intended to hide the joint under my step pads.  This would only a short straight line on either side that did not align.  My hope is that the bolts of the step pad going thru the two boards would help mitigate any movement in this area in the future as the boat moves.
My first attempt was terrible.  I could not get the joint tight.  Despite 3 hours of block sanding, rasping and block planing, I just could not get the fit I wanted.  I finally determined that I was leaving a small crown and not getting a square edge
So, I came up with an idea of using a router and down spiral bit size 1/8in. 
It worked perfectly.  The technique would work on any pattern joint.
a. rough cut the joint and clamp the boards securely in place
b. clamp a straight edge to use as a guide for the router  so that the router bit will besect the rough joint.
c. set the router bit to only cut the depth of the board
d. slowly run the bit down the joints
e. clean out the joint of debri and slide the board together