Charlie, first of all welcome aboard. The subject of oars, oar length and oar lock location can be both straightforward and opinionated. Depends upon who you ask. I am going to quote from a previous post made by Dave Zelinski, a builder of beautiful boats and more. I will provided the straightforward math method he provided someone else;

"A starting point.....

Width between oarlocks divided by 2, then divide by 7 then multiply by 25 then minus 6 inches...

So...60" across the oarlocks...as is the case with my flyfisher skiff...

((60/2)/7)*25 = 107 inches, minus 6 = ...divide by 12, viola! 8.4feet.  Go with an 8 or 8-1/2 footer depending on what feels good to you.   I like an 8 foot oar in this boat.

Or the case with my 16x48..... 64" across the oarlocks.... yields a 9.02' calculation.  However, personal preference for this boat is 8-1/2' oars.

I have a set of retired ash oars.... New Zealand "Gull Oars" and they are beasts.  I only use them in whitewater.  I made a few sets of laminated spruce/fir oars that I prefer as they are very light and flexy.  Most of the water I float is Class dos or less.

Another way to look at is is to decide you inboard length of the oar... alot of old school recommendations are for a 7/18 leverage ratio. 

For example, let's say I want 28inches of inboard oar. Let's figure out the outboard oar length....the formula becomes:

Outboard length = (18/7)*(inboard length)

outboard oar = (18/7)*28 = 72 inches.  add this to 28 = 100 inches. divide by 12 = 8.3 feet. Viola! an 8 foot to 8-1/2' oar.

Math is fun.

lifting weights is not."

With that being said personal opinions and experiences based on type, materials, design and intended use all impact the choices made for oars. If you can find someone in Casper that has a driftboat see if they will loan you a set of oars for a trip. Then borrow a different style and length. Oars can be handcrafted from solid lumber or laminated from one or several types of wood. They can be thin and fine with small blades or big and heavy with thick, wide blades. Carbon fiber, hickory, spruce, aluminum etc.

Oar lock location, I'm surprised that the plans don't offer a suggest as to placement. Oh well, there are a couple of ways to deal with that. You can do some testing with temporary oarlock blocks and some clamps. Set in your boat and try some locations that seem comfortable to you. I personally like to have the oars perpendicular to the boat with my hands resting on the handles and my elbows aligned vertically. That might work for you too. Comfort will tell you a lot. Another option is to make an oarlock block with multiple locations a couple of inches apart and you have options. High Density Polyurethane makes a good oarlock block. It machines easily and is slick allowing the oarlock itself to move with little friction. A couple of bolts through the inner and outer gunwhales and you are good to go.

A feature of Wooden Boat People's site is the search bar located on the top right hand side of the page. A search for oars returned 10 pages of links. Try it and see if it helps. If not feel free to ask questions and someone will come up with an answer.

Rick Newman