Yes and absolutely it does.

Solutions range from shoving something into the slot to some truly beautiful fitted wooden slot covers.

Have fun,

Laszlo

The answer to both of your questions is, "Yes."  You'll want to stuff something into the daggerboard slot to keep the water from shooting up.  If there is much wave action at all, it'll pump enough water up into the boat that the Oarsman's Wet Seat Syndrome will be the least of your concerns.

I've seen photos of some rowing/sailing boats with daggerboards using fitted "plugs" of a T-shaped crossection where the lower part conforms to the slot itself (sometimes all the way to being flush with the bottom of the slot for less turbulence below), and the broader top part is inlet into the top of the rowing thwart for a flush fit.

I've successfully used a couple of old mouse pads overlapped and folded over and then stuffed into the slot open edge down.  Lately I've gone to a pair of foam insulaltion strips with the adhesive backs stuck together and a short loop of sash cord between the two layers so I can get a finger in to pull it out qluickly.  Neither solution fills in the slot opening below (probably not a big deal on the PMD, performance-wise), but it keeps my behind dry when rowing.

.....Michael

P.S. Those were good questions, not dumb ones.

I enjoy rowing and built my Skerry primarily for that purpose, It's great exercise and the Skerry gets along very nicely. I rarely sail as I'm not much of a sailor although a neighbour often takes her out for a spin. To counteract the wet backside I made a dummy daggerboard with a top shaped to match the centre thwart. On top of that I have a pad made from a piece of camping sleeping mat cut to the shape of a Concept 2 rowing machine (I have one of those too for the winter workouts) seat pad. The photo shows the basic plug. Because I keep the boat in the sea for 5 or 6 months I treat the bottom couple of inches of the plug with anti foul the same as I do the bottom of the boat. 

Safe to assume that this same issue applies to the eastport pram?  Noticed that the nesting version includes a flush mount daggerboard plug, but my non-nesting version does not, so I assumed it was not an issue.  Thanks all...