Lot's depend on where you want to row, how deep the water might be. Typically when rowing you want to steer with the oars, feathering the one on the side you want to turn towards. A rudder will increase the waterline effect when kept straight to the keel, helping you keep to a steady heading while resisting turning if that's your intent. A 'board in the water helps this same effect but more when it's windy & you find yourself being blown off course despite your best efforts with that leeward oar to compensate.

If you only have an inch or two under your keel you may need a pole....

I took my dory up to Maine for a week of coastal camp cruising last summer.   Figured we would mostly be sailing, but there was no wind almost every day.  So we ran into this same question.  What worked best for us was to pull the daggerboard while rowing, but leave the rudder in place.  The rudder with the fixed transverse tiller is just such an awkward shape that there is nowhere to put it in the boat.  Also, if the wind comes up and you want to sail again, reinstalling the rudder while bouncing around in swells or chop can be devilishly difficult.

Remove the tiller extension and just let the rudder feather itself when you row.   I also have cleats mounted on the inside of the hull just below the rails about 2 feet forward of the transom.   I found that tying off the tiller extension connector line to the cleat on the side of the boat the tiller sticks out to helped keep it from flopping around -- in one direction (leave enough slack so that it can turn a little to the opposite side). 

I also made a plywood cap for the daggerboard trunk.   That keeps water from splashing up through the trunk while you're rowing.  Also is much quieter that way!  It is secured with a webbing strap and quick-release plastic buckle, the ends of which are screwed to the sides of the trunk with brass finish washers.  This also holds the daggerboard down when sailing.

   Great comments from both of you. I really rowed quite a bit today and found much better with the rudder and dagger board out. And I agree, difficult to find the right spot for the rudder and tiller extension. 

Just another question to fellow NE Dory sailors.  As a beginner sailor I am having difficulty tacking to get to a location in the direction from where the wind is blowing in. I come about easy enough, and hold a tack at maybe 45 degrees off the wind but invariably the wind blows the bow such that I end up going downwind.  To prevent this I tryto use the rudder but then that creates resistance which slows me down and makes things worse.  Any comments would be helpful  ..

   Hello Clark, good questions all. I'm new to the row/sail game my self having just over a season under my belt. I'm going to build a kick up rudder. When it's up you get no resistance except maybe a little windage and it's only a matter of pulling a string to engage it. Look down the threads a few notches for a long discussion on kick up rudders.
My Dory started pointing much better when I really tightened the corners of the sail on yard and mast. Also moved the halyard back a few inches on the yard which puts a little more sail in front of the mast. That made a huge change from heavy lee helm to slightly weather helm. Seem more efficient to have a more neutral helm. Finally I really hall away at the downhall which reduces sail twist some and makes the sail a better wing shape I think.
Tinkering with the downhall and halyard attach points pays dividends. Have a search for Goat Island Skiff pages. Those guys are Lug Rig Evangelists and total freaks about getting the last degree on the wind.
It's a lot of fun tinkering with this stuff once you get a bit of a handle of what's doing what. Good luck,
ev

Agree on the sail trim comments from Eric...I'll dig into another angle:

Tacking a light weight boat:

RE: your comment: "I come about easy enough, and hold a tack at maybe 45 degrees off the wind but invariably the wind blows the bow such that I end up going downwind.  To prevent this I try to use the rudder but then that creates resistance which slows me down and makes things worse.  Any comments would be helpful"

I think I can add a comment that may help...might also draw other contra comments, let's see. 

When tacking any sailboat the heavier it is, the more it will maintain speed in the tack, thus maintaining sail shape, thus lift, thus power thus speed.  A 12,000 pound keelboat is so hard to slow down that it can power thru a tack and barely slow down if the crew is fast enough on the sails.  However, any light weight smaller boat (like any CLC stitch and glue boat) is so light it doesn't take much to slow it down in the tack, thus loosing sail lift if you sheet it in to normal set for that line, the sail is acting like a brake, as is the rudder.  I had sailed many small day sailors but even so it took me a while (duh) to figure out how to tack my CLC dory.  I found that the trick is to ease the rudder into the tack as far as you can before loosing speed, then throw it over, but not hard over (thus a stall), and with whatever speed you maintain in the tack, let the sheet out quite a ways so it maintains sail shape, and slowly sheet in and simultaneously (slowly) bring the rudder back to point up to your 45 degree tack.  Going slightly off the wind after the tack and sheeting out a fair amount to maintain helm/speed, then slowly bringing in the sail and pointing up at the same time will increase speed quite quickly...almost all in one motion.  Maintaining speed is more important than loosing a few degrees of point on the tack, so..tack, fall off, sheet out, sheet in and point up to gain speed.  Hopefully you wont go WAY down wind like I did the first few times.

OK, from all the great sailors on this forum, I'd love to hear other techniques!

Curt...

   Yes Curt, that is exactly what I  found to work today. I was determined to reach a target upwind and kept trying things until I evovled to your techniques and method. 

The big thing was actually giving up a little in direction to regain speed by letting sails out and then pulling in.  So I made my target and the Wind died to zero

Good thing the dory rows well.

Thanks for everyone's comments.  Still having fun,,,