I currently own two Nicaraguan Boas. They are a related male and female, 2010, from a Columbian Motley female and a Nicaraguan male. They are currently about 3 foot long, and still quite slim. I would expect the male, Leonard, to get to about 4 foot and the female, Joan to be a little bigger, but no bigger than 5 foot.
They will both form an essential part of my breeding program, probably from 2014 onwards, although I might try Leonard with a Blonde Albino or a Hypo Salmon next year.