They claim that a fish wraps line around your ducer and it cuts through the insulation and frys your unit,if you send yours in for service and they ask you how far below the ice you hang the ducer beware,thats their out.Keep an eye on the ducer,if the insulation starts to pull back from where it goes into the top trash it.Then they fix it and send you a bill for $160 to get your unit back.Thats Marcums customer service for ya.
Go Helix 7,use it on the boat and the ice.