The half model, traditionally, was cut into sections and then scaled. But, any error in measuring, etc. will be magnified when you blow up the offsets. Lofting is the intermediate process that is designed to find/correct those errors. Computers do it now but in the old days (and still on larger scale projects) the offset table was used to make a drawing like the one below. Each waterline and buttocks (fore/aft vertical slice) is plotted and a batten is used to connect the lines. That way you can predict how the material will lay and then find any errors. Some points may not be fair and a new point can be determined. Corrections are made to the offset table and then molds are drawn. The loftsman regularly made corrections to offset tables from even the best naval architects (White, Hershoff, etc.).

Most people skip this step. It's not required if you're already working with full size plans. It may be overkill for your iceboat too but that's what lofting is.

- Chip

PS: I already know I'm a pain in the ass, my wife tells me every day