The solo flats skiff 13 is considered both a fishing kayak & a one-person skiff. purchase our kayak plans to learn how to build a fishing boat easily & quickly.. Spira international wooden boat plans. following are the stock plans available for the various types of boats, separated into the different categories.. Osprey 18 flats skiff. the osprey 18 flats skiff was originally designed for a client (who stiffed me on half his bill!) in louisiana back in 2008..