Early Season Ice Checking

 For people on foot or with light sailing craft.

 A big, smooth sheet of new ice gives most of us ice fever.   Early season new ice is also some of the most unreliable ice.  This combination makes early season ice especially prone to swims.  The following is a general procedure for checking new ice.  You may need to adjust it for your specific situation and risk tolerance.   This procedure is intended for getting a feel for what hazards exist.  It is not comprehensive enough to find every hazard.   In general, if you find one hazard (like a new ice-hole) you can expect there are more of them elsewhere on the ice sheet.    It is recommended that your first few ice checking trips be with experienced ice checkers.  

Recommended equipment (in rough order of importance):

• Ice claws
• A similarly equipped friend or two
• Test pole, axe, ice chisel, drill or other test device of your choice. 
• A life jacket or other flotation is strongly recommended
• A dry or wet suit is recommended
• Throw rope or 50 feet of line.
• Helmet, foot traction and/or skates
• Tape measure or scale for accurately measuring ice thickness (it is much better to measure than estimate) 
• A GPS to put in waypoints for hazards.  A camera with a GPS function makes this easy. 
• A waterproof or expendable digital camera is handy for taking pictures and making verbal notes on short videos.

 Recommended preparation

• Review the weather history for the previous week.  Pay particular attention to above freezing temperatures and wind when above freezing.  See if you can identify when the ice came in.  Snow falls are also important
• If you can visit the lake a day or two  after the ice starts so come in,  you may be able to spot new ice holes and other open water  that may be thin ice later.
• If you can find someone who spends a lot of time on the lake, ask them about persistent hazards.
• Practice with your test pole (or other assessment tool) enough to get a sense of how it behaves on different ice thicknesses.
• If it is above freezing, consider waiting until it gets colder. Sunlight can weaken ice quickly, especially in the spring. It also also can be much quieter than cold ice, robbing you of much of the cracking noise that reminds you that you are on dodgy ice. 
• Arrange for a suitably equipped companion or two to accompany you. 

When you get to the ice:

• Resist the temptation to check the ice if you are not fully prepared (eg:  you don't have your ice claws, friends, etc). 
• Observe the ice as best you can from shore.  Look for open water,  jumbled ice, frozen ice edges, etc.  Binoculars and any a higher vantage point are both helpful.
• Talk to anyone in the area who has been on the ice.
• Use your test pole to test the ice as you move a little ways onto the ice and measure the thickness (knock a piece out with your pole, drill the ice, etc).  If it is 2" or less, come back when it is thicker.
• If the ice is sufficiently thick (at least 2" and preferably 3 or 4"), walk or skate over the ice you want to check.  In particular look for open water, dark areas in the ice that could be recently frozen open water, wet cracks, gas holes, drain holes, etc.  Use your test pole a lot. 
• Stress cracks can be a reasonable way to estimate the thickness.
• Cracks that form as you move along should be considered a warning sign until proven otherwise.   Multiple cracks, especially with a circumferential crack a couple feet out, probably means you are in Wily E. Coyote territory.
• Warm water holes and frozen ice edges account for a lot of early swims.   If you find frozen new-ice holes test their thickness.  All the holes may not freeze at the same time.
• Frozen ice edges are best approached from the older/thicker side.  Typically the oldest ice is near the shore and at the back of bays.
• Check snow drifts to see if they have thin ice or gas holes underneath.   Isolated gas holes will be hard to find if there are lots of drifts on the ice.  
• If you are going to skate or sail after checking the ice, it is best if you mark problem areas.  Branches sticking out of holes, cones, flags, and Christmas trees have all been used.
• After you have walked/skated on the ice you intend to sail on, start off by sailing slowly so you can recheck the ice.  In most cases you will cover a lot more ground when sailing than when ice checking.

Some hazards you might see:

• New-ice holes
• Early season gas holes (in new ice they can be hard to see.  If you see  bunches of marsh gas bubbles in/under  the ice, check the area carefully for thin spots)  More...
• Frozen ice edges: As you approach one from behind you typically see a sequence of wave-break cracks, broken ice, jumbled ice, often a slush ice band around forms around the broken pieces.  A white splashout rim at the edge and, finally, dark new ice on the other side.  The new ice may be white from slush that the wind accumulated against the ice edge before it froze.
• Wet cracks and leads, frozen or open
• Pressure ridges (they usually don't show up until the ice gets 2-4" thick). Expect them to form across bay mouths, along shore and across the lake between points. Crossing ridges on thin ice is tricky...eiher wait for the ice to thicken find what appears to be a good crossing.  Don't linger on the weak parts of the ridge. 
• If it has been warm expect drain holes and, possibly, puddle holes.
• Thin ice associated with inlets, outlets, reefs, etc
• Swamps and flowing water (rivers or  narrow places in lakes) are likely to have thin areas. 
• If the top layer is snow ice (frozen slush) be especially careful.   Determine if the slush is frozen all the way through and expect that it might not be elsewhere on the ice sheet, especially under any dry snow.   If there is any question about the slush being completely frozen, make sure the underlying black ice is over two inches thick.  (more...)

 Lloyd Roberts wrote an excellent article on ice checking in the NEIYA newsletter.  In my opinion his minimum thickness recommendation make his approach oriented to more experienced ice checkers with a relatively high risk tolerance.  (Click Here)

 Eric Anderson talks about the checking for DN sailing near the beginning of his article on clothing.  (Click Here)

 One last thought:  When you report on what you find, make sure your ice fever is not talking.  You will  quickly get a bad reputation if you tell people the ice is better than it is.  Stick to what you found and what hazards you have good reason to suspect.  Give an idea of where you looked and where you did not.  Along the same line of thinking, take all ice reports with a grain of salt until you have checked the ice yourself.  Even with a good report, the ice may have evolved between the time the check was made and when you get to the ice.

 Bob