See how much ice your de-icer will clear.
Pick your coldest winter, water depth, mount and motor. We draw Kasco's published opening to scale around real boats and docks, then match it to the unit, cord and control panel that fit.
Your starting setup
Control panel · one per de-icer
Mounting
Tell us your site in the cart notes and a Kasco-trained tech will double-check the size before it ships.
Compare motor sizes
Many slips? Seawall? Moving water?
Text us a photo or a quick sketch of your layout and a Kasco-trained tech will mark up where each unit should go, free.
Where the numbers come from
Every opening on this page is Kasco Marine's published de-icer sizing chart (2026). Kasco measures them on unobstructed water, on a large, deep lake, with more than 4 ft of water at the unit.
What shrinks the opening
Shallow water, current, steady wind, hulls, pilings and breakwalls all make the real opening smaller than the chart. When the choice is close, size up.
Keep hydro in check
A thermostat panel only runs the unit when the water needs it. See what a winter of de-icing really costs in our running-cost guide.
De-icer sizing questions
Still unsure? Call or text 1-855-752-5795 and talk to someone who has had these units apart on our bench.
What size de-icer do I need for my dock?
Start with the coldest week you need to hold through, not the average winter. In the −18 to −7 °C band a vertically mounted ½ HP Kasco 2400D opens about 50 ft of water, the ¾ HP 3400D about 70 ft and the 1 HP 4400D about 80 ft. Colder sites lose a lot of that, so if your choice is close, go one size up.
Should I hang my de-icer vertically or at an angle?
Vertical gives a round opening around one point, ideal for a boat lift, a single slip or a cluster of pilings. Angled pushes a long, narrow lane along the surface, the better choice for protecting the full face of a dock, a seawall or a row of slips.
How deep does the water need to be?
Kasco's minimum is 4 ft at the unit. We prefer 6 ft or more: deeper water holds a warmer bottom layer for the de-icer to lift, and the unit is less likely to stir up sediment.
Should I choose 120V or 208–240V?
Both open the same water. The HD (208–240V) versions draw about half the amps, which helps on long cord runs and busy dock circuits. The ½ HP size is 120V only.
How many de-icers does a marina need?
More than dividing the basin by one unit's opening suggests, because hulls, finger piers and pilings break up the flow. Plan on at least one unit per slip or lift you need to protect, and send us your layout so we can mark up positions with you.
Can one control panel run several de-icers?
No. Kasco's C-10 and C-20 panels are each built to control one unit, so plan one panel per de-icer.