ok two mistakes (sort of ) that you might not want to make.

1) when you cut the sides on your drift boat cut the long line that divides the two halves and face the same sides together before you cut the bow and transom, this way if you have a slight difference in color between one side or the other they end up the same. whether you use it for the inside or outside of you boat if you, as I did, cut it the way its layed out on the drawing you have one inside and one outside piece so your color is slightly different and also you tend to have a better looking glue joint on one side to the other this is all if you go natural or stain your wood if you paint it it doesn't matter

2) secondly if you have a clean and tightly made scarf joint I don't think you need filler if you wet it out enough and use enough epoxy that way when you mate them together the little bit of squeeze out is clear and not milky from the filler, which helps when you add additional layer of epoxy you won't have to sand it off and possibly lighten the area around the joint