I have been aware of the Orca plugin pretty much since it came out. AFAIK it will help you quite a bit on generating the curve of areas automatically so you can see what section changes do. As lofting surfaces IS a History feature in Rhino you can simplify changes and reiterate pretty quickly. I'm not sure you will need much more than that as it's quick to give the CofBuoyancy anyway. Try and find someone else whose has used Orca or is still using it - likely better on keelboats and will probably give righting moments etc. I liked Rhino 5 and ran it on a Win 7 box. Went straight to rhino 7 upgrade but jumped OS to Win 11, I think that's why I missed Ver 6 it would not install into Win 7!. I jumped XP, 8 and 10, no biggie.
It's really important to consider the dynamic of a hull through the range. You will find some that probably have great static figures but bury the nose easily as you can't sink the stern. No CAD system is going to give you that feel. My own 'feel' is that 12 foot boats are hard to get right whether single or double handed especially plane take off and staying on the plane. I've built a couple this sort of length, the second genuinely competitive even after 15 years. At 14 feet plus boats are a lot easier and just go fast enough for it to be far less of a problem. There's a certain small kids rotomoulded boat that took 5 prototypes to get right - proof that small boats are harder design work. It was worth it, the sales have been very very good. If you want another example, the stern of some designs becomes extended with heel - look at 2.4 meter yachts so they suddenly drag water further along the rear sections and extend their displacement speed window upwards. The more different development class boats you can sail the better you understand small changes in design and their effects. Having spoken to at least half a dozen qualified naval architects at the relatively small scale of dinghies what you build is the test prototype. Bear in mind that even here 3mm on a section can be worth 100m in a mile on a reach (I'm pretty sure Jo Richards found that out with his F Dutchman), though I stand to be corrected.
On getting a smooth shape hull in the UK we have a Class called National 12s and their rules allowed a 4 plank construction when they developed a cheaper alternative to full clinker back in the 1970s'. They went smooth ie not overlapped planks at the same time - so three chines per side plus keel. The designers found how close they could get to a fully cold moulded smooth hull at the time, this is where the 3mm max deviation from a perfect smooth shape comes in. Note this does not stop a deliberate chine... especially aft.
Currently the hard stuff is primarily in foils and all that entails with airborne hulls, look how fast that changes in Moths.
It's really important to consider the dynamic of a hull through the range. You will find some that probably have great static figures but bury the nose easily as you can't sink the stern. No CAD system is going to give you that feel. My own 'feel' is that 12 foot boats are hard to get right whether single or double handed especially plane take off and staying on the plane. I've built a couple this sort of length, the second genuinely competitive even after 15 years. At 14 feet plus boats are a lot easier and just go fast enough for it to be far less of a problem. There's a certain small kids rotomoulded boat that took 5 prototypes to get right - proof that small boats are harder design work. It was worth it, the sales have been very very good. If you want another example, the stern of some designs becomes extended with heel - look at 2.4 meter yachts so they suddenly drag water further along the rear sections and extend their displacement speed window upwards. The more different development class boats you can sail the better you understand small changes in design and their effects. Having spoken to at least half a dozen qualified naval architects at the relatively small scale of dinghies what you build is the test prototype. Bear in mind that even here 3mm on a section can be worth 100m in a mile on a reach (I'm pretty sure Jo Richards found that out with his F Dutchman), though I stand to be corrected.
On getting a smooth shape hull in the UK we have a Class called National 12s and their rules allowed a 4 plank construction when they developed a cheaper alternative to full clinker back in the 1970s'. They went smooth ie not overlapped planks at the same time - so three chines per side plus keel. The designers found how close they could get to a fully cold moulded smooth hull at the time, this is where the 3mm max deviation from a perfect smooth shape comes in. Note this does not stop a deliberate chine... especially aft.
Currently the hard stuff is primarily in foils and all that entails with airborne hulls, look how fast that changes in Moths.
