Dories are a comfortable, exciting way to travel the river.  They are about 17-18 feet long, have a wide, flat bottom, flared sides, and a pointed stern. The beam at the oarlocks is about 6 feet with a 4 foot width at the bottom.  You will also see an upward rake in the prow (front) and stern.  This helps them to turn easily and power up and over waves.  They have benches with back rests and the passengers sit on cushions (it is a very comfortable ride!).  You have hand holds in front of you and also will tend to grab the gunnel for support.  Your feet are in a well, which is one of the few areas that will fill up with water when swamped by a big wave.  They have secure compartments for your stuff that are very water resistant (note:  did not say waterproof!).  The boats we rode were made by Andy Hutchinson (High Desert Dories)  They are made from epoxy / fiberglass over plywood with hardwood gunnels and handrails.  There were five dories on our trip (19 customers) and one large S-rig motorized support raft that carried all the gear.

You can see the mechanics of a dory ride above in this sequence shot.  The boat rides up high over the wave then drops down into the trough before recovering.  Suprisingly, very little water comes in when the waves are hit head on.