i am planing to set up a slackline in a lake. for this i will use a A frame type set up. the only problem about this is that there is no way to stake the line for an anchor and no to park a car over the line which have been discussed in previous forums. so i have decided to use weights (ie concrete or similar stuff) for the anchor and i was wondering if any one knew how mush weight would be needed to make this set up work. the line will be used to jump on so it will have to be tight and i will use a 3 pt anchor system on each side. sorry for teh rambling and thanks for the help
