Currents are specifically mentioned as a possible challenge at some of our dive sites and can be present anywhere at any time. We always check the currents before diving.
We do not do drift dives. Drifting ice is a real hazard. If it comes in while divers are underwater, it can be very hard to see people if they surface in the middle of it. Icebergs should be either hard aground or floating in water well clear of brash or pack ice.