Chuck, You have asked so nicely that I will make an effort to simplify the wake speed limitation mystery. The bow wake is produced by pushing (displacing) the water at the bow. The stern is actually doing just the negative of the bow. Anyway as your boat increases in speed you can see the bow wave trough and crest advance toward the stern. Eventually you will obtain enough speed that the trough and crest go all the way to the stern and the bow and stern are both sitting across a single trough. That is you hull speed. As the boat's speed now increases the stern falls into the trough and you are headed up the back side of the bow wake. That is why additional power seems to do little in the way of increased speed. If you were in a planning boat you would have the power to make it up the bow wake and be on plane at which point you could power down. That is where the classic formula of hullspeed=1.34*sqrt(LWL) comes about. Others have rightly recognized that the 1.34 is rather general and have suggested that the 1.34 be replaced by something more along the lines of a variable that is related to displacement and LWL. I believe that Gerr was one of the more recent to make this suggestion. However, that too, is likely and empirical simplification since it is also likely dependent of the form. Since most boats have a reasonably decent form then displacement and LWL is likely a step up form 1.34. The displacement and LWL concept also demonstrates why a catamaran is inherently more efficient or as efficient at higher speeds. Assuming both hull are totally independent, a catamaran would only have half the displacement per LWL as a monohull. That doesn't translate to twice the speed, but would increase the hull speed of a typical 40-45 ft catamaran by 20-25% over the monohull. So the answer to your question about possible interference that could occur between hull, the answer is yes. At some speed the reflection of the opposite interior bow wakes could bounce back to the hulls. However, since the force on the hulls would be perpendicular to the direction of travel it isn't clear that it would be a problem until the tunnel were filled with water and forced forward to interfere with the bow wake. Although it might try to raise the stern before that occurred. Unfortunately what little research is done in these areas is mostly proprietary and not publicly published. The only research money actually available is from the government and that too is held in secret. Bill Fleenor PS - Georgs asked about the Double-Wide progress. Not as quick as I might have liked, but the product continues to impress me. I still keep updating the work at http://groups.msn.com/TrawlerMV/doublewide.msnw. Do yourself a favor and just go to the end of the photos.