Justin,
depending on the curve, that could be right, but you usually go for what full advance is. For cars, full advance is usually 28. On boats, you can get away with A LOT more, up to 38 on pump gas depending on your compression. I would take it out to the lake/rive and play with it. If it predetonates (ping/knock) then turn it back a touch, and test again.
I got a great low cost tip for timing here on the boards, that will give a more power on the bottom end. Lock out your advance - so you get no advance(there may be a screw already in the dist for doing this, or you may need to add one). Set the timing at 38. If your starter can't turn the motor over with this advance, run a cut-off swith on the power to the coil. With the switch off, turn the motor over and when it is turning at full speed, turn the switch back on and vroooooom. Again, test the advance for knocking and pinging, and dial it in. You can try some octane additive (prolong makes one that is about as good as they get).
A more expensive route is to go with an MSD. You can get a start retard and knock retard built in, but you have to pay for it eek! . That was the route I took.
I am sure you will get a lot more tips on timing.