Wetsuits are not generally comfortable for rowing. Because they are tight-fitting and insulating they tend to have the shortcomings that are mis-attributed to PFDs. That being said, in recent years a great deal of sophisticated design has gone into designing wetsuits for triathletes, and these tend to be very flexible and chafe-free while offering some buoyancy and warmth in cold water. These might be suitable for your cold-water rowing.
First of all, they come in all sorts of configurations from full body suits with hoods to shorts, vests, or uni-styles like most rowers are accustomed to wearing. Secondly, they are warm and – more importantly – keep you warm in cold water. That’s what they were originally designed for. Thirdly, the offer some flotation; not as much as a PFD, but more than lycra, wool, or fleece. Fourthly, the come in many thicknesses with the thinner ones offering more flexibility and the thicker ones offering more warmth and flotation. Finally, modern wetsuits consist of neoprene sandwhiched between more skin-friendly materials like cotton and polyesters. Properly fitted over base layers they can be pretty comfortable.
If you are rowing casually in cold weather and on cold water, there are a range of wetsuit options you may want to try.