plywood boat hard to row

+1 on what's been said on skegs. And DEFINITELY experiment with fore & aft trim.
As to oars, knock on wood, longer's better, & yours may be a touch petite. They're not cheap, but a 7'-8' set will make a gigantic difference in pulling power - just ask Archimedes (re; levers). And when cared for, good oars last a Long time.
If you've the inclination, you can even whip up a pair yourself, there are plenty of designs & building tips available online.

PS: Stan Grayson's "The Dinghy Book" has a good bit of outstanding info on how to setup/design a dinghy for comfort & performance. It's definitely worth the price of admission.
http://www.amazon.com/Dinghy-Book-S...id=1403131520&sr=1-1&keywords=the dinghy book

 

I would disagree with U/C on oar length. I understand the boat is hard to row. For a light, easily-driven small boat a longer oar gives higher gear but for a boat that is hard to push changing to longer oars will just make it harder, like pedaling a bike uphill in top gear. The ratio of outboard to inboard length of oar determines the gear ratio. The inboard length is determined by the beam, which is not very big. You can overlap the oar handles but that takes more skill and there's a limit to how much overlap you can have. You don't have a lot of freeboard (gunnel to water) so the oars are probably rather flat on the pull stroke; adding oar overlap will subtract from that so the oars may hit your knees, compensating for that by driving the blades deeper may reduce control and efficiency, neither of which seems too good at the moment.

Solve the tracking and drag problems the best you can. If it then seems there is more speed to be had comfortably, look at longer oars. Of course, it would also depend on whether speed is valuable, how far do you have to row, you're presumably just getting to your favorite fishing spot and back . . . and there's the cost of the oars too; the other things you need (move load, add skeg) are cheap.