O.K., a little late but hopefully still helpful. I like Kent's idea and use it almost exclusively, but, would alter your technique to get it to work right. When I work in this way, I apply the glue sparingly, with a straight pin or needle, dipping it in the glue and dotting and spreading it in the gap, then applying the sliver of wood, and tape down with "drafting tape". The drafting tape will hold, and not peel wood up with it when you take it off, like masking tape can. Refrain from smearing glue on anything if possible, as you don't want the glue to seal the wood, and with a splinter such as this, it will seal the whole piece and then you've lost the color and reason for using the little piece of wood in the first place. It doesn't take much to hold the piece in, and when you finish over it, you will have an almost invisible repair. This one, the owner may not even see!! If you are careful, and select the same grain as what you are repairing, you will be surprised how it will disappear when you finish the piece. Just hold back on the glue. More is NOT better here. There is NO strength required, so, you are just trying to hold it in place until the finish makes it one with the boat. Even the best wood/flour type filler will have different characteristics than the actual wood and glue doesn't take a finish as well. The wood fibers will, but the glue will be solid and shiney and will resist the epoxy or what ever you put over it. The only thing that will match wood, is more of the same wood. Takes a little extra work, but....:) :) :)

Rehd