CROSSING CURRENTS

Guiding Principle

Most kayakers can paddle around 3 knots. Currents can be much faster than that on the sea. Throw in some wind and some swell, and they can change a paddle from a leisurely cruise to a white knuckle experience.  Adjusting for current through dead reckoning and piloting is critical to good seamanship.

Performance Objectives
  • Paddlers should plot a course adjusting for current.
  • Paddlers should use piloting to cross current.
  • Paddlers should determine ETA when crossing current.
  • Paddlers should demonstrate where to find tide and current information.
Materials
  • Props for ranges/transits.
  • Eldridge/Reed’s.
  • Scratch paper and pencil.
  • Orienteering compass/parallel rules/Nav-Aid.
  • Photocopy of Charts.
  • Varying difficulty of problems depending on knowledge and skills of paddlers.
  • Moving water.

CONTENT

Crossing current using piloting

Ranges/Transits

  • Line up two fixed points and keep them stationary in relation to one another.
  • Requires constantly adjusting heading in relation to current and destination
  • Monitor progress using auxiliary ranges/transits.
Crossing current using dead reckoning
  • Draw a line from departure point to intended arrival point (rum line).
  • Find distance and determine estimated crossing time without current.
  • Determine direction and speed of current at intended time of departure. (Use Coastal Pilot such as Eldridge/Reed's.)
  • Draw the direction of current from departure point (set).
  • Determine the distance set and mark on set line.
  • Draw line from distance set to arrival point. The bearing of this line will be the heading. The length of this line will be ‘real’ distance traveled, thus time for crossing can be estimated.
Crossing current in the real world: the Art of Navigation

The reason navigation is an art: in reality, we often use a combination of piloting and dead reckoning when crossing a current. We consult tide and current tables and have an idea what the water will be doing when we intend to cross. We may plot a course ahead of time if the currents and/or the crossing are significant. When we get to the crossing, we look for cues like:

  • Current flowing past lobster/navigation buoys: near and far away.
  • Path of boats working or traveling across crossing.
  • Direction and velocity of the wind especially in relation to the current.
  • Distinct or indistinct eddy lines, swirls, boils, foam, and general water texture.
  • Direction and size of swell, especially breaking waves.

Once we start the crossing, we find the intended course, determine whether to paddle upstream and use the current, or to cross right there. We keep track of ranges/transits to monitor our progress. We also look at other kayaks in our group/shoreline behind us to monitor progress.

AND WE ARE CONSTANTLY THINKING:  Where will we go if the shit hits the fan?

Practice, practice, practice – even when you don’t need to, because someday you will.

Where to find current information

Information on tides and currents is published in print, online, and on computer software. It takes practice to interpret this information from printed tables. Paddlers should be aware that what happens in the real world can vary considerably from published information.

Tasks/Activities
  1. Assign a crossing current problem to students. Be sure that they have plotting a course down before they attempt this exercise. The difficulty of the problem should depend on the ability and experience of the students.
  2. Start with hypothetical situation with current at right angle to desired course and nice even numbers.
  3. Move to current at differing angles but keep crossing relatively short.
  4. Finally, crossings of multiple hours, solving the problem for each hour.
Assessment Tools
  1. Paddlers should know what a range/transit is and how to apply them to crossing a current.
  2. Paddlers should know how to plot a course.