Nautical Science P1 MG 2017 hlayiso.com

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE EXAMINATION NOVEMBER 2017 NAUTICAL SCIENCE: PAPER I MARKING GUIDELINES Time: 3 hours 150 marks These marking guidelines are prepared for use by examiners and sub-examiners, all of whom are required to attend a standardisation meeting to ensure that the guidelines are consistently interpreted and applied in the marking of candidates' scripts. The IEB will not enter into any discussions or correspondence about any marking guidelines. It is acknowledged that there may be different views about some matters of emphasis or detail in the guidelines. It is also recognised that, without the benefit of attendance at a standardisation meeting, there may be different interpretations of the application of the marking guidelines. IEB Copyright © 2017 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: NAUTICAL SCIENCE: PAPER I – MARKING GUIDELINES Page 2 of 7 SECTION A PRACTICAL CHART WORK QUESTION 1 1.1 COURSE Cape Point brg. Slangkoppunt Lt Compass 16:00 022° 084° 042° Deviation 4° E 4° E 4° E Magnetic 026° 088° 046° Variation 26° W 26° W 26° W True 000° 062° 020° 16:00 to WP.1 course to make good 008° (T) 29,6 m WP.1 to WP.2 course to make good 030° (T) 9,7 m WP.2 to WP.3 (Pilot) course to make good 090° (T) 2,7 m Total distance = 42,0 m. (See chart for full answer) 1.2 From 16:00 to WP.1 Course to make good 008°(T) Course to counter current 001°(T) See chart Leeway 5° - Course to steer 356°(T) Variation 26° W Magnetic course 022°(M) Deviation 4° E Compass course to steer 018°(C) 1.3 Distance to go from 16:00 is 42,0 m Speed 14 kts, duration 3 hrs, ETA Pilot 19:00 IEB Copyright © 2017 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: NAUTICAL SCIENCE: PAPER I – MARKING GUIDELINES Page 3 of 7 Q1 (ctd.) IEB Copyright © 2017 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: NAUTICAL SCIENCE: PAPER I – MARKING GUIDELINES Page 4 of 7 QUESTION 2 2.1 Bearing between Hangberg & Chapman's 148/328° Dissect at 90° for centre of position circle Bearing between Chapman’s Peak & Slangkoppunt 030/210° 90° – 98° = 8° Slangkop 030° + 8° = 038° Chapman's Peak 210° – 8° = 202° V/l position 34° 06' S 018° 20' E (see chart for full answer) 2.2 Depth of water in that position is ≥30 m. 2.3 The index error will be checked by observing a star directly through the sextant with the following procedure: • Set the sextant index arm to 0°. • Observe the star and adjust the index arm to bring the star and the reflected object together so the two coincide perfectly. • The reading will then be the Index Error (IE). If it is 0° there is no IE. If the reading is +ve, or ON the arc, then the IE is subtracted. If it is –ve, or OFF the arc, then the IE is added. QUESTION 3 3.1 Course 13:15 Bearing 13:45 Bearing Compass 349° 304° 259° Deviation 2° E 2° E 2° E Magnetic 351° 306° 261° Variation 26° W 26° W 26° W True 325° 280° 235° Position at 13:45 34° 12.6'S 018° 38'E (See chart for full answer) 3.2 Distance off Whittle Rk. at 13:45 is 3,8 miles. IEB Copyright © 2017 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: NAUTICAL SCIENCE: PAPER I – MARKING GUIDELINES Page 5 of 7 QUESTION 4 4.1 Height of tide required = Draught + UKC + drying height = 10,7 + 2,0 + 1,1 = 13,8 m 4.2 • Currents are permanent or seasonal horizontal movements of water flowing in a particular direction. • The result is a uniform movement of water in a given direction that transports a vessel bodily without affecting the ship's head. • Tidal streams are also the horizontal movement of water but caused by tidal forces. • They can be rectilinear (flowing in two directions called ebb and flood), or rotary, changing direction 360° in a cycle. 4.3 Information about tidal streams and currents can be found on the chart, in the Sailing Directions and in a special Tidal Stream Atlas. IEB Copyright © 2017 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: NAUTICAL SCIENCE: PAPER I – MARKING GUIDELINES Page 6 of 7 SECTION B ASTRO-NAVIGATION QUESTION 5 Observation  Sun 09h 14m Chron (given) 21s 09h 14m Chron (AM) 18.08.1987 21s − 01m Error (fast) 25s 09h 12m UT/GMT 18.08.1987 (Z) 56s sin Hc = cos LHA ∙ cos L ∙ cos D − sin L · sin D Tab GHA  314° 00,8’ or sin Hc = (cos LHA − 1) ∙ cos L ∙ cos D + cos ( L + D) + 003° HA Inc  14,0’ + 012° LHA > E Longitude sin Hc = (0,65672) 07,0’ 180° East of LHA  329° 21,8’ Hc = 41° 03’ 01,2” Ship Tab Dec  N 13° 13,5’ N  Hc ⇒ 41° 03,0’ − 000° (d − 0,8’) Corr X 00,2’ Dec  N 13° 13,3’ Q cos CZD = cos LHA ∙ cos L ∙ cos D − sin L · sin D ZX = QZ + DR Latitude 25° 35,0’ S QX Z or cos CZD = (cos LHA − 1) ∙ cos L ∙ cos D + cos ( L + D) Lat + Dec 38° 48,3’ N ZX = (L + D) S Lat and Dec S/N Opp − cos CZD = (0,65672) CZD = 48° 56’ 58,8” A = |Tan L ÷ Tan HA| 0,80836 N CZD ⇒ 48° 57,0’ B = |Tan D ÷ Sin HA| 0,46105 N C=A+B 1,26941 N ∠Z 41,13386° (Nearest Zc N 41° E ½°) (Nearest LOP Zn 041°T 131°T ~ 311°T  ½°) Direction Hs  LL 41° 07,9’ IE (on) − 01,0’ OA  LL 41° 06,9’ Dip (12,0m) − 06,1’ AA  LL 41° 00,8’ TC  LL + 14,9’ (Aug) Ho  41° 15,7’ TZD  48° 44,3’ Hc  41° 03,0’ CZD  48° 57,0’ 12,7 miles 12,7 miles Intercept  Intercept  Towards Towards (Ho > Hc) (TZD < CZD) IEB Copyright © 2017 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: NAUTICAL SCIENCE: PAPER I – MARKING GUIDELINES Page 7 of 7 QUESTION 6 6.1 LMT Sunset 15° N 18H 22M Long. 10° 25' W + 42M GMT 19H 04M Zone (+1) - 1H 00M Sunset v/l time 18H 04M Dec 18 Aug 19:00 13° 05.4' 'd' (-0.8) 00.1' Dec 19:04 13° 05.3' 6.2 Sin Amp. = Sin Dec. / Cos Lat = Sin 13° 05.4' / Cos 15° = 0.234470708 Amp. = W13 1/2° N True brg. = 283 1/2° Comp. brg. = 302° Comp. error = 18 1/2° W Var. = 26° W Dev. = 7 1/2° E 6.3 Comp. course 276°(C) Error 18 1/2° W True course 257 1/2°(T) Total: 150 marks IEB Copyright © 2017