Advanced Navigation Test: Sailing Questions & Answers

Plane Sailing - ANSWERSRegards the Earth as a plane surface. Uses a triangle to solve for: - True Course - Distance - Difference of Latitude - Departure Plane Sailing Limitations - ANSWERSDoesn't solve for Longitude of Arrival or DLo. Short distances only (a few hundred NM). Solves for Rhumb Line only. Great Circle vs Rhumb Line - ANSWERSGreat Circle - the shortest distance between two points along the surface of the earth. Rhumb Line - a line on the surface of the earth making the same oblique angle with all meridians. Plane Triangle Points - ANSWERS- P1 = Point of Departure - P2 = Point of Arrival - L1/L2 = Latitude of Point of Departure/Arrival - Lam1/Lam2 = Longitude of Point of Departure/ Arrival Difference in Latitude (l) - ANSWERS- D.Lat (l) = Difference in latitude between P1+P2 - Units = NM or minutes - Labeled N if P2 is North of P1 - Labeled S if P2 is South of P1 Departure (p) - ANSWERSDistance in NM between Lam1+Lam2 measured E or W along with the parallel of latitude through P2 - Labeled E if Lam2 is E of Lam1 - Labeled W if Lam2 is W of Lam1 Distance (D) - ANSWERSDistance NM between P1 and P2 Course Angle (C) - ANSWERS- Measured from True North or True South (whichever one is closest) - Must be converted to True Course (Cn) NE Quadrant - ANSWERS000TCn090T C = Cn C is labeled NE SE Quadrant - ANSWERS090TCn180T C = 180 - Cn Cn = 180 - C SW Quadrant - ANSWERS180TCn270T C = Cn - 180 Cn = C + 180 NW Quadrant - ANSWERS270TCn000T C = 360 - Cn Cn = 360 - C Plane Sailing Formulas - ANSWERScosC = l/D l = D(cosC) D = l/(cosC) sinC = p/D p = D(sinC) tanC = p/l Traverse Sailing - ANSWERSUsing a series of courses and distances determines course and distance made good between departure and arrival and a Traverse Table. Traverse Table - ANSWERSColumns for N, S, E, & W. - N & S = l; l = D(cosC) - E & W = p; p = D(sinC) - Must calculate C based on Cn for each leg - You must calculate l and p for each leg - Plug your answers into the appropriate column; solve for Cn and D Parallel Sailing - ANSWERSNavigational calculations while sailing due E (090T) or due W (270T) - Sailing on a "Parallel of Latitude" - Given distance traveled, Parallel Sailing enables calculations of DLo - Gives results in NM (1' LAT = 1 NM -- l) Latitude vs Longitude - ANSWERSLength of 1 degree longtidue varies with the latitude. 1 degree = 60NM at the equator 1 degree = 0NM at the poles Longitude vs Latitude - ANSWERSLength of 1 degree longitude is directly proportional to the cos of the latitude - Length (NM) = Lam (in min) * cosL Parallel Equation - ANSWERSLength (NM) = Long. (min) * cosL (L=Lat) - p = DLo*cosL - p/cosL = DLo