I performed a test; NidaCore vs. Plywood for my own information, but thought I would pass along my findings. I had no other reason for doing the test than for my own personal information. I think some of you will find this information interesting. Test parameters: Both core materials measured 18" x 48". 3/4" thick NidaCore vs. 1/2" marine plywood. The 3/4" NidaCore was covered on each side with 1-layer of 1708 and then 1-layer of .75 oz mat. The mat was used to cover the 1708 to create a smoother finish. The 1/2" marine plywood (no voids, good stuff) was covered on each side with 1.5 oz mat. The mat adds very little if any strength, but it is what I use to seal plywood in bulkheads. The weight difference between the 2 finished materials equated to 15 lbs per 4'x8' sheet. So if you were to use say 30 sheets of 4'x8' 1/2" plywood to build your boat, you would save 450 total pounds by using the NidaCore instead of the plywood. Those sound like good weight savings, but it gets better. The NidaCore was way more rigid and stiff than the plywood (which surprised me a little bit). For plywood, marine plywood with no voids is pretty strong/stiff material. I've always been satisfied with it's strength. I'm just estimating here, but I would guess that you would have to jump up to at least 5/8" marine plywood to equal the rigidity/strenth of the 3/4" NidaCore. 5/8" plywood is about 11 pounds heavier per 4'x8' sheet than 1/2" plywood, so now the weight savings for a 4'x8' sheet of NidaCore is about 26 lbs lighter than a 4'x8' sheet of 5/8" plywood. 5/8" marine plywood is sturdy material in my opinion, but the NidaCore blows it away in weight savings. I'm not trying to say that NidaCore is superior in every way, or that you should use NidaCore in all your builds, projects, repairs, etc. But when you simply look at weight, I'm estimating a 600 - 1,200 lbs weight savings on a typical 36'-38' boat if you use all NidaCore vs. all plywood. There are a lot of variables in exactly how much weight you would save by using NidaCore, but I think a 600 - 1,200 lbs savings would cover most DE boats in the 36' size range. The bigger the boat, the more weight savings; smaller boat, less weight savings. For the way I build my boats, I'm estimating a 600-700 lbs saving. I'm estimating the extra material cost for me will be about $3,500 more to do all NidaCore vs all plywood. And obviously some more hours of labor for the NidaCore.