Before the trip

Plan where river crossings need to be. Find out about current bridges and route options. Forecast what you will experience when you do get to a river. And never be surprised when the bridge, weather, flow, the crossing, or anything else has changed.

Practise everything in training especially swimming with a pack,  feet downstream, avoid trapped boots, head bumps, obstacles.

Before you get your feet wet

Assess the river and make a deliberate judgment of the difficulties v your abilities, before you start to cross

Choose the best place to cross

A track marker on both sides doesn’t always mean you are at the best place, rivers change faster than track markers move.

Decide - where is the hardest point going to be?

Patience may be required waiting for level to drop

Rivers often fall after rain as fast as they rise

Glacier rivers may be lowest in the morning, before the daily melt

Rivers range in type, each may need you to use a different technique

Wider faster and shallower may be best

Slightly slower deeper  may be harder

Much slower  and deeper (swimming?) may be easier for some  teams

Multi smaller channels can be an easier series of crossings than one combined flow

Check straight quiet sections between bends

At the top of an island can be wide shallow faster

Shallowest calmest best crossing often at the tail end of a pool  before the top of the next rapid.

Look for long diagonal shallow bars

Prefer crossings that allow you to angle down river

Plan for everything that could realistically go wrong.

Identify exit and escape routes

Assess continuously while you are crossing, back out if needed

Avoid -

Staring at moving water while crossing - is often disorientating

Cold shock, losing strength, multiple crossing hypothermia

Outside of bends -  faster water and scouring deeper

Downstream of junctions - more water, often swifter and deeper

Smaller stream crossings right above a big flooded river

Faster than walking pace flows

Heavily discoloured water, about to rise, obscuring 

Murky glacial water hiding details

Deep channels on the far side

Unexplained surface turbulence

Mobile bottoms - small gravel washing from under your boots obstacles

Large boulders under water with larger holes between them

Slippery slabs

Uneven bottoms

 

Beware Stay out -

Of flood water – the speed and power of the current will be increasing dramatically with seemingly minor increases of river level

If boulders are knocking / moving in the flow

If branches logs debris are floating past

Water flowing into branches or debris

Do -

Keep boots on - protect feet

Remove overtrous / clothing  even gaiters to minimise flow force

Free your hands to link up - put away most poles.

Keep quick release Hip belt done up - helps if you need to swim

Chest strap unclipped – avoid strangulation

Waterproof packing – dry gear floats better

 

Cross diagonally downstream, with the current, minimise the flow force

    ....faster flow – means more drift and space needed

    ….for teams – means stay in line with the flow and step on an angle

Small steps – better control and balance

Step between the rocks - for the same reasons.

Plan for flow force increasing dramatically as thighs, torso, pack get in the current

   ...and feet have less grip as you start to float

 

Mutual support –

A group linked securely is many times stronger than a person solo.

Tallest strongest heaviest person on the up stream end - will take the force of the water

-they will often be the most experienced leader, or will need to work closely with leader\co-ordinator

Second strongest may be best anchoring bottom end

What the leader/head end can stand against or cope with will determine what can be successfully crossed

Rest of team stay strictly in line with the flow, sheltered from the flow force, coordinated with and supporting the leader

The headend/leader must not be washed or pulled off their feet

From two to six or more people in a team? But will require more space and coordination.

Everyone communicate clearly, coordinate movement, stay linked in line

Back out if required by backing out, don’t turn

Stay locked together, and communicating, especially when swimming

Linking between any two people can be high, low, very close or extended as dictated by the conditions. High and wide gives more flexibility on uneven bottom.

Both parties of each link need to be able to independently brace themselves and never have to let go.  Grip packs, straps clothing. Don’t just hold hands or link arms.

Pole method (goes back to pre-European times)

A strong heavy pole helps keep the team in line and gives the head end maximum support

 

Solo method

Trekking Poles are helpful but not as strong as

Using a single 2m+ pole as a tripod third leg, held on the upstream side

Keep legs in line or facing slightly into the flow

Move one point at a time

Back out if necessary

 

Rope techniques

Can be useful when no other method could work.

Use as a last resort, after you have practised extensively in training situations.

Useful on short crossings when to be swept away is death

Rope usually needs to be twice as long as the crossing

Cross one at a time

Belay as far up stream as possible to provide support against the current

Always plan prior for what will happen when you have a ‘swimmer’ on the end of the rope.

Do not set up ‘handlines’ or any form of overhead handheld ‘support’.

 

Back on the bank

Look back and learn.

Eat drink change to dry clothes perhaps, stay warm.

 

More Hints paraphrased from feedback

" polarized sunglasses are a great help. They can make the bottom significantly easier to see which reduces the chance of a misstep."   

"The use of a rope can be quite complicated ... It must be possible to recover the person crossing should they lose their footing. There must be no risk of the rope snagging on rocks or logs and at least one spare strong tramper on the same side as the belayer." 

"Crossability is affected by the depth and speed of the water, the nature and smoothness of the river bed, the temperature and clarity of the water, the width of the river and the run out."  

"People have drowned because they thought a rope made them safer."

"Some swift water professionals also recommend a mutual support technique where the group forms a narrow triangle supporting the leader at the apex"

All of the above (except polarised sunglasses and the triangle method) are included in the river crossing section of "Safety in the Mountains" Robin McNeil 2012.

more info -

http://www.mountainsafety.org.nz/assets/images/About%20river%20safety(1).pdf