Hi Bruce...

Thank you for your reply.

You hit the treenail on the end! Cribs are notorious for moving, especially in the winter.

I planned to do a piling dock. About 2X the cost of a quality crib dock, but a better bet to survive winter. A contractor looked at my waterfront and felt thier was not sufficient rocks and stones on top of the bedrock to prevent a piling dock from moving. Drilling into the bedrock would be 50% more then simply driving the pilings. So...I go with a crib, or a drilled piling at 3X the cost. Yeeks! The good news is that this contractor in not a fan of cribs, but felt if there was an ideal location for a crib dock, my waterfront was it (little wake from ships, partially protected by a small bay, ice known to melt in the spring with little to no movement from water flow...). I thinking maybe an ice melter could protect the crib from vertical ice movement as the water level increases.

As an alternative, I'm looking at the possibility of having pilings with a plate on bottom end that could be pinned to the bedrock. It would be closer in cost to a driven piling than a drilled piling...I hope!

You sound familar with the St Lawrence river. Where are you from? I think I'm pushing being off topic with this thread...I'd love to continue talking via email perhaps?

Joel