I need scuppers or drains for my decks. Ideas?

The decks are flat and at a 90 degree angle to the topsides.  There is a 2 inch gap between the outboard edge of the deck and the inside of the topside planking.  This is due to the 2 inch thick frames which you can see in the photos.  I believe the best way to drain water off the decks will be to have drains in the decks that take a 90 degree turn outboard and drain through the topsides.  There are some very expensive bronze fittings made for the this application, but it seems to me there must be a cheaper way to do it.  I need to research this.