LBP
(1) Length between perpendiculars (LBP) means the horizontal distance measured between perpendiculars taken at the forward-most and after-most points on the waterline corresponding to the deepest operating draft. For a small passenger vessel that has underwater projections extending forward of the forward-most point or aft of the after-most point on the deepest waterline of the vessel, the Commanding Officer, U.S. Coast Guard Marine Safety Center, may include the length or a portion of the length of the underwater projections in the value used for the LBP for the purposes of this subchapter. The length or a portion of the length of projections that contribute more than 2 percent of the underwater volume of the vessel is normally added to the actual LBP.
Source
46 CFR § 170.055
Scoping language
Assumed average weight per person means the weight calculated in accordance with 170.090 of this part.