Tips on Slipping a Course

Written & compiled by Suzy Danielson, A TD

Slipping a course, for either training or a race, is important as it keeps the race course fair, the training course skiable and both courses SAFE by cutting down on injuries. No one keeps the perfect line all the time (although we wish we do) and a lot of people find themselves outside the line, trying to get back in the course (some of us with more flourish than others). When there are snow piles/slush piles outside of the line, it could result in possible knee injuries (acl’s, etc.) or boot top injuries. That is why we slip outside the line to move those snow piles out of the way of potential travel. NOTE: For the newer people, the “line” is the ideal track down the course. Side slipping a course is typically done and should be done by SIDE slipping, not snowplowing (with exceptions). Below are excerpts from an article written by Sean Florian (a USSA coach and Level 3 TD), indicating the pros and cons of both techniques.

General slip techniques

Side Slipping

Side slipping is performed by slipping down the hill with your tips and tails perpendicular to the fall line, slipping over the snow leaving a smooth track. This method is the least disruptive to the snow surface and leaves the best possible track to race on. The best method of initial side slipping for assisting in course prep is to pick one side of the course and go straight down the hill. You do not want to follow the gates or the line. You should have two or three of your race buddies follow you tip to tail. Each skier will leave a small pile of snow on his tip or tail. Each person in your group should overlap the person in front of you in a staggered formation, slipping out their trail in the snow. With 4-6 people in slalom, you can slip the whole track and not leave one pile of snow if there were no piles to begin with. If everyone performed inspection in this manner, there would be little or no work at all to prepare the course. If you are slipping and inspecting, or slipping during a race, slip outside of the line to push away berms and built up snow.


Snowplowing is performed by pointing your tips straight down the hill in a wedge position plowing the snow off the sides of your track. This will leave large piles on the sides of your path, which gets larger and larger as each racer goes by in the same manner. The disadvantage to this method is the amount of snow piled up on the sides of the course and at the base of the gates is very dangerous. If you are on course in the right line, it is no problem. But if you get out of kilter, your chances of injury increase exponentially. Since we have a few diligent racers and resort race departments that make sure everything is safe, we rarely start a race with those conditions, but it is a great deal of work to get it that way. In some cases we will have to send down 10-15 racers several times to perform quad burning efforts to push the piles off the course. As you can see snowplowing causes more work and a less desirable track to race on. The only case where a snowplow becomes necessary is when the section of the hill is too flat to sideslip, and you have to snowplow by pushing or pulling yourself along with your poles.

Different types of snow and inspection techniques

Hard Snow

Side slipping is the method of choice for inspection and course preparation, using the tip to tail method. If snowplowing is used, it produces a sugar type snow that piles up at the base of the gates and in the low line. As we all know carving a turn in sugar is almost impossible and slow as well.

Hard Crust over Soft Snow

This type of condition occurs after a warm spell or rain, and one night of cold. Small controlled groups should be allowed to do a tip to tail slip, but the main inspection should be performed by side slipping outside the course. To get a look at the line, stop in each section, outside the course, and glide in on a railed edge to look at the line. When you are done with that section or gate, glide back out. If we don't follow the glide in and out method, we will scrape down through some of the crust. The first few racers will get by ok, but by the mid 30-50's holes will start to develop, and people will start pre-releasing from their bindings. In some cases salt or fertilizer will be applied to the surface 30-40 minutes prior to starting which helps harden the snow. No one is allowed on the course except race crew during that period to allow the chemical to set up.

Fresh Powder Snow

If it is a light dusting of snow, following the methods for hard snow will work fine. If it is more than 2-3 inches, then organized slips need to be performed. Groups of 6-12 people should perform tip to tail slips with all skiers letting the snow out the same side of the hill. If the snow is real deep (so you can't see your skis) then you will need to walk your way through by moving your skis up and down and shuffling your feet. This will free you up from the snow and push it at the same time. In extreme cases we will have to hand pack the snow with our skis in a side slip / side step fashion, or even climb as mentioned in an earlier method.

Fresh Heavy Wet Snow

This is the most difficult situation to deal with in racing, and is controlled by the race organizer and the TD to ensure proper course conditions. In some cases, a light slip over the top of the snow by several experienced slippers followed by salt will work. In other cases, repeated tip to tail slip groups will gradually push all the soft snow to the side of the trail. Snow plowing in this situation will result in extremely heavy piles of snow that are very difficult to remove. In these conditions, it is very important to follow exactly what the race crew and TD recommend.

Soft Spring Snow

With this type of snow, you are usually dealing with areas that have thin cover. Those areas will normally be blocked off with gates. Please stay away from those areas to prevent premature break through. Again the tip to tail method will work best here to prevent piles.

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