Question and Answers

    Question
    marinetales July 27, 2021
    The depths given on a Nautical Chart (whether in meters, foot or fathoms etc) are measured from the Chart datum. Common chart datums are the Lowest Astronomical Tide or Mean Low Low water tide. For Non-tidal areas Mean Sea level (MSL) values are used. The echo sounder gives the depth BELOW KEEL. Let us assume that Echo Sounder is giving you a fairly accurate reading. In order to compare both (Echo sounder and Chart readings) following shall be used - Depth on Chart = Depth obtained from Echo Sounder + draft of the vessel - Value of Tide at the given place Above is just an assumption and the values could be affected by the rolling/pitching, sea conditions and other meteorological phenomenon such as High-low pressure systems.
    marinetales July 26, 2021
    Synchronized pitching is when the period of the vessel pitching, equals the period of encounter of the waves from either ahead or astern. It must be considered extremely dangerous especially if in an area of abnormal waves. It can be overcome by reducing the ship’s speed and changing the period of encounter.
    marinetales July 25, 2021
    Engaging with tugs must always be considered as a high risk area of work and as such the following points would go some way to making the task as safe as possible: (a) Clarify beforehand the method of engagement as to whether the tugs line is to be used or the ship’s line and which ‘lead’ is intended. (b) All persons involved in the operation should be adequately kitted out in protective clothing and briefed as to the nature of the activities involved. (c) Adequate communications, tested beforehand, should be available between towing stations to the bridge and the towing vessel if appropriate. (d) If the tugs line is to be used, this should be inspected to be free of defects and be seen to be of adequate strength. (e) Throughout the operation all personnel should be advised to keep clear of bights in wires/ropes. (f) The eye of the towline should not be placed on the ‘bitts’ but the wire should be set in a figure ‘8’, turns, around the bollards. The top turns should be lightly lashed to prevent accidentally jumping off. (g) Non-essential personnel should be kept well clear of towlines and the towing area.
    marinetales July 25, 2021
    The advantages of the Mediterranean Moor are: • That more vessels can berth with restricted quay space. • Cargo ships can work both port and starboard sides into barges. • Tanker vessels can load/discharge through stern manifolds. • Roll on–Roll off (Ro-Ro) vessels can operate stern ramps. The disadvantages are: • The vessel is exposed from the shore. • Cargo ships are denied the use of shore side cranes. • Loading and discharge must take place into barges. • A boat is required to go ashore.
    marinetales July 24, 2021
    The fouled anchor is the description given to when the anchor itself is fouled by some object like a cast off fishing wire, or even by its own cable turned around the fluke. A fouled hawse occurs when the vessel has moored with two anchors and ship’s anchor cables have become entwined, usually caused by a change in the wind direction, causing the vessel to swing in opposition to the lay of cables.
    marinetales July 24, 2021
    Short stay is a term used to express a short amount of visible cable at a steep angle from the hawse pipe to the water surface. Whereas long stay is a term which describes where the cable is in a more horizontal direction towards being parallel to the surface of the water. The cable is said to ‘grow’ from a shorter stay to a long stay aspect.
    marinetales July 24, 2021
    By watching the cable after applying the brake once the required scope has been played out. If the cable rises up, to long stay and then bows, to form a ‘catenary’, then rises again. This cable movement is an indication that the vessel is riding to her anchor not dragging her anchor. If the cable stays taught all the time it may be assumed that the anchor is dragging under the tension.
    marinetales July 24, 2021
    Good Holding Ground : Mud and clay Bad Holding Ground : Ooze, marsh, soft sand, rock, pebble.
    marinetales July 23, 2021
    OA represents the apparent motion of the target. WA represents the true course and speed of the target. OW represents own ship’s motion (course and speed).
    marinetales July 21, 2021
    Place the engines on ‘stand-by’ and the situation may make it necessary to take all way off my own ship. Further actions would include: (a) Advising the Master of the situation of the vessel aground. (b) Carrying out a ‘chart assessment’ to include my own ship’s position and the position of the vessel aground. (c) Switch on the echo sounder and note the Under keel Clearance. (d) Position lookouts and turn from auto pilot to manual steering. (e) Communicate with the vessel aground, with station identification, obtaining the draught of the aground vessel and the time of grounding. (f) Carry out an assessment of the extent of the shoal that the vessel has run aground on.
    marinetales July 21, 2021
    The OOW remains the Master’s representative in the absence of the Master, despite the presence of a pilot (exception Panama Canal). During any pilotage period he would be expected to maintain an effective lookout at all times. In addition, he would continually monitor the ship’s position by primary and secondary means and ensure that the under keel clearance is adequate throughout. His duties will also include the management of the bridge personnel and he would ensure that the pilot’s instructions are executed in a correct manner by the members of the ‘bridge team’. He would further ensure that the pilot is made familiar with the bridge instrumentation and advised of compass errors and any defects which may affect the safe navigation of the vessel.
    marinetales July 21, 2021
    While taking over/keeping an Anchor watch, the OOW shall comply with the procedures laid down by the company's SMS through means of a checklist. Such checklist may contain following - 1. maintain an effective lookout, by all available means, including visual, audible and radar. 2. check the position at regular intervals to ensure that the ship is not ‘dragging her anchor’ 3. Position monitoring by primary and secondary position fixing methods, i.e. checking Visual Anchor Bearings, Radar Range and Bearings, Global Positioning System (GPS) etc. 4. Monitor the state of visibility, the state of the weather, especially wind and tide changes 5. Traffic movement in and out of the anchorage 6. Listening watch on VHF 7. Log books to be maintained 8. Access to the ship to be monitored and ISPS to be complied with
    marinetales July 21, 2021
    The OOW should call the Master in any of the following circumstances: (a) In the event of visibility dropping below 4 miles (company policy may be more or less than this figure). (b) If traffic was causing concern effecting the safe passage of the vessel. (c) In the event of failure of any of the ship’s navigational equipment. (d) If failing to sight a landfall when expecting to. (e) If sighting a landfall when it is unexpected. (f) If soundings are shelving when unexpected. (g) In the event that difficulty is experienced in maintaining the course. (h) If a scheduled position is unattainable or suspect. (i) In the event that the man management of watch keepers becomes untenable. (j) In the event of heavy weather or on receipt of a bad weather forecast. (k) On sighting ice, or receiving an ice warning of ice being reported on or near the vessels track. (l) If sighting oil on the surface. (m) On any issue of security or shipboard alert. (n) In any other emergency, such as fire or flooding, imminent contact or contact with a submerged object.
    marinetales July 20, 2021
    Following shall be done in case the restricted visibility is encountered - (a) Place the ship’s main engines on ‘stand-by’ and reduce the vessels speed. (b) Advise the Master of the change in visibility conditions. (c) Commence sounding fog signals. (d) Switch on the navigation lights. (e) Close all watertight doors in the vessel. (f) Commence systematic plotting of any targets on the radar. (g) Place a current position on the chart. (h) Post additional lookouts. (i) Stop all noisy work on deck. (j) Enter a statement of actions into the ship’s Deck Log Book.
    marinetales July 7, 2021
    one diamond shape when the length of the tow is 200 meters or less
    marinetales July 7, 2021
    4 short blasts on the whistle
    marinetales July 6, 2021
    Slowly and repeatedly raising and lowering arms outstretched to each side.
    marinetales July 6, 2021
    Reduce to minimum steerage way (in case target is not detected by radar).
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