Assistance Towing Endorsement

Assistance Towing - Stranding


Welcome to Captains Marine On-Line.  We are dedicated to providing you with a premier learning opportunity.  It is imperative that you complete all parts of this course as crucial information is contained throughout the curriculum.   Course completion should take approximately 4 hours.  Access to this course will expire one year from the date of enrollment.

The purpose of this course is to prepare a Captain to assist a vessel in need of a tow.   This course enables you to tow a disabled vessel for hire, not for commercial barge towing.

Captain Flynn Smith is the narrator for the audio portion of this course.  This audio lecture provides explanations for many important concepts contained in this curriculum.  To begin, find the play button for the audio lecture.  Clicking the button will begin the audio, which will play while you follow along reading the text.  Using the player controls, you may pause the audio at any time or replay a section.  The audio lecture can be reviewed as many times as needed.  Exam questions can be derived from text, audio, videos, and diagrams.  It is important to read and listen to all the content, as well as complete all practical exercises and quizzes.

Materials needed for this course are a calculator, pencil and paper.

Syllabus and Course Framework

Time:  4 hours

Lesson Objectives:

  • The learner will know the proper procedures for a stranding situation.
  • The learner will be familiar with the principles behind towing.
  • The learner will know proper towing maneuvers.

Materials Used: 

  • Text, audio lecture, videos and diagrams

Stranding: Assisting and Getting Assistance

The first consideration when assisting another vessel is to keep your vessel from joining the other craft that is in trouble.  Factors to consider are the size and weight of the grounded vessel relative to the power of your engines as well as the draft of your vessel relative to the water depth.  Also you should consider the level of your skills in the situation.  If you feel that you can safely and effectively assist the vessel, then follow proper towing procedures discussed in this course. 

If your vessel goes aground, the first instinct is to gun the engine in reverse to pull off, but this is the one thing that you should not do as this could damage your rudder or cause raw water intakes to clog.  If you intentionally make a blowhole (prop dredging) the fine is $1,000 or more ($100 or more for an unintentional blowhole).  The first thing to do is check for leakage.  If there is none, the next thing to do is to check the state of the tide.  If the tide is rising and the sea is calm enough that your hull is not pounding, time is in your favor.  If you ground on a falling tide, quick and precise work is important.  Check the water depth around your vessel to note where the deeper water is.  You will be familiar with the shape of your hull and its point of greatest draft.  If the hull tends to swing to the action of wind or waves, the pivot point is the part grounded.

The next important consideration is the type of bottom.  If the bottom is sandy and you reverse hard you may wash sand from astern and throw it directly under the keel, which would make the grounding worse.  If the bottom is hard and you reverse to free your vessel you may do more damage to your vessel. 

The correct thing to do immediately after grounding is to set a kedge.  Take out your heaviest anchor and set it firmly. Pulling on the anchor may break you free. This is kedging.  If you have a dingy, use it to take the anchor out to deeper water let the line run from the stern of the dingy as it uncoils. Fasten the bitter end of the line to the vessel’s stern cleat as you head back towards the grounded vessel. If you don’t have a dingy you can swim the anchor out, but be sure to wear a PFD and buoy the anchor to save your energy for the work that you need to do.  With a sailboat, it is usually helpful to put out a kedge anchor with a line running to the top of the mast to heel the boat over, thus reducing draft.  For a mono hull sailboat, a 60 degree heel will reduce the draft in half.

Consider the turning effects of your vessel when reversing and set the kedge at a compensating angle.  For example, if the propeller is right-hand, set the anchor slightly to starboard of the stern.  The effect will be that when pulling the kedge line while in reverse, the vessel will tend to back in a straight line.  Make sure to always keep the kedge line taut during the entire grounding.  This may allow the vessel to free itself when a wake from a passing boat lifts the vessel.  A pulley, such as a “handy-billy” can also be used for more effective pulling.   Remember that a long splice is designed to pass easily through a block and tackle much easier than a short splice.

Handy Billy

Two kedges set at acute angles from either side of the stern may give the stern wiggle to help work the vessel clear.  Shift heavy objects and people away from the grounded area.  For a sailing vessel, if you have spars, swing the boom outboard and put people on it to raise the keel line.  If you have a dingy you can move heavy objects to the dingy.

The above procedures are all good things to do if the vessel hull has not been breached.  If there is a hole in the hull, it may be best to leave the vessel where it is until help arrives and a patch can be made.

If your vessel is going to be left high and dry during a falling tide, keep an eye on its layover condition.  Make sure that you close all of your sea cocks. When the water rises it may back siphon back into your boat before it begins to float.

Whenever you are in a grounding situation, either as the grounded vessel or providing assistance to a grounded vessel, safety should always be your first priority.  People on the disabled vessel should don PFDs.  You can assist a vessel that has grounded even if you do not actually provide a tow to that vessel.  As every situation is different, you can draw on your own knowledge to best provide assistance.  A cargo net or Jacob’s Ladder, which is a rope ladder with wooden rungs, can be used to assist in retrieving people from the water.

If a vessel is broken down and rolling in heavy seas you can reduce the danger of capsizing by rigging a sea anchor.  When a boat turns broadside to heavy seas and winds, thus exposing the boat to the danger of capsizing, the boat can broach.   When there is plenty of sea room, a vessel with a sea anchor and a relatively small center of gravity will ride easiest in a heavy gale with the vessel drifting.  With a following sea, remember that a vessel will tend to yaw (surf down a wave).

Drogue (Warp)

Sea Anchor

The first important maneuver to assist a stranded vessel is to get a line over.  The most common way to accomplish this is to motor over, passing the line, and backing out again.  This should only be attempted if there is sufficient water for your vessel.  Wind and current, as well as your vessel’s backing maneuverability will affect this procedure.  There are other ways to pass a line if you cannot safely pass it in this manner.  A monkey’s fist on a heaving line would be one method.  The disadvantage of using a heaving line to pass a towline is that recreational boaters tend to make the heaving line fast to the towed vessel as if it were the towline.  Remember that polypropylene line will float.  A knife or another sharp instrument should be available in the event a line needs to be cut quickly.

Try backing in using the wind and current to your advantage, leaving your bow headed out.  After the line is passed and made fast, do the actual pulling with your engines going ahead to get full power.  For greater maneuverability, make the line fast as far forward of the stern as possible.

If a close approach isn’t possible, you can drop a kedge anchor for the grounded vessel and use a dingy to pass the line over.  You can even buoy the line and float it over.  Make sure the line is fastened properly and is not frayed as it could snap under high tension. 

The stranded craft should have a kedge out for control when it comes off and another anchor ready to prevent the vessel from going back aground, especially if it has lost power.  All lines must be kept free from the propellers, and all persons on the vessels should be as far away from the lines under tension as possible.  Make sure that there are no sudden surges put on the line.  Remember that recreational vessels are not designed as tugboats and cleats and bits may not be strong enough for the strain.  A bridle around the whole hull of the stranded vessel may be the best and safest way to secure it.  A bridle can be used on your own vessel as well. 

If you are pulling with your vessel underway, secure the tow line well forward of your stern to keep your position and maneuverability.