Ducklings take longer than chicks, so let them be for a while. I had 2 in my last hatch that took 40+ hours, and turned out perfect. I was preparing myself to step in at 48 hours, but mine made it out just before that. Talk to them, sing to them, keep them active and vocal ... but don't panic and help too soon.
Thanks everyone. A couple look they are now trying to pip a little ways from the first pip. Hopefully when i get home later there will be some progress.