I filled most of the cracks in the yellow cedar area of the deck. You can see that there were quite a few of them, primarily down the centerline and in the areas where the yellow cedar met the red cedar. I used a filler composed of epoxy resin and sanding dust from the yellow cedar.

Here's a close-up of some cracks filled on the front part of the deck.

Here's a close-up of a major gap where the yellow cedar meets the red cedar.

And here's a look at the back of the the boat. You can see that I got a little sloppy, though the excess should sand away rather quickly. What's next? Well, first I want to sand the cockpit coaming. I've borrowed a detail sander (Ryobi DS-1000, thanks Dale!) that should do the trick nicely. Then I'll start to fill the gaps in the red cedar, both in the cockpit and elsewhere. I'm sure I'll have another round of the sand-n-fill shuffle until it comes time to fiberglass.