hydrostatic underwater weighing

i just got tested with this technique in my applied nutrition class. my question is...would a cheat day the day before significantly affect my bodyfat from this test, since im more bloated today and holding more water? (muscle cells are more filled as well=superhydrated). i have my measurements but no calculator since im in the library at college as we speak. water density is .994...residual volume 1.1....weigh 180lbs...height 70", water bodyweight 27.75lbs, residual volume 1 L (i think)...if anyone can calculate my body density id appreciate it (im lazy LOL)...heres the formula... body weight in air/[(body weight in air-body weight in water)/water density] - residual volume+.1=body density then you plus body density into this equation for bodyfat... (4.950/body density-4.500)*100 (siri equation) im in school with no calc and theres hardly anyone in here lol...so if ya can figure this out id appreciate it...ill calculate it at home anyway but im really in interested in what it is...with the skinfold test last week with thigh/abdomen/chest measurements it was 11%..but i think its off because the equation doesnt account for resistant trained individuals..plus it was only three spots to take skinfolds from..so not THAT accurate...