Originally Posted by Dick L.
Obviously not Bob - since moving ballast is also illegal in most (not all) classes. Once you hang a "blob" of lead under a hull, regardless of design it really does become a displacment hull of one level or another.
There are photos of models that "appear" to be ready to plane - or that actually may have exceeded hull speed for a moment or two - but to sustain planning over any distance/time by most models is as you post, pretty rare if indeed it happened.
I won't touch on the subject of foils in this post, nor on asy spinnakers or multihulls - all of which could lend themselves to further speculation/argument. Would leave this to strictly the IOM class. Too easy to hijack a thread with examples or speculations. Just wanted to point out there are other ideas that approach or exceed true wind speed - but to my knowledge the IOM isn't one of those designs - (right now).
It is for exactly this reason that I simply do not the modern trend for hull forms more suited to a dinghy than a yacht. The photo of GPZY's Southern Bell is fantastic but look closely at the water and it shows how that boat is desperate for slightly wider shoulders (15mm a side directly under the no 36 on the jib) and slightly narrower hips and legs. The result would be a resist that heel and all that power would transmit backwards.
BTW I would buy a Southern Bell based on those 2 photos, I would fit a jib trimmer and have myself a very nice boat.