Here are the directions on how to make a template for us to use in order to make a custom windshield for a boat that is not already in our inventory. 

Take a roll of tape and overlap each piece one after the other around the windshield area.

Each cowling is different and you might need to go horizontally or vertically or even a few different angles the most important thing is to overlap all the pieces so when your done you can remove the tape as 1 piece and apply it to a piece of paper to be scanned or mailed to us to produce the finished product.

To outline the shape take a pen or marker and go around the inside of the recessed area if it has one. 
If there is no recessed area like the photo shown then you will have to try to draw the shape of the windshield.

Try to make it as clean as possible we can adjust things on our end if necessary but the better the provided outline the better the end result.