As of fall 2018: Due to the massive area flooding event in spring of 2013 - the visibility at Lake Minnewanka is still very poor (6-12 ft) with some improvement but still lots of silt & debris in most areas. Also watch for some entanglement hazard from branches, logs, etc, which is also greatly increased. Water levels lately are often very low and often fluctuate which is normal for a reservoir - depending on the time of year, rainfall, snow melt, etc., (and power draw requirements from town of Banff).
"Safety Marker or Dive Flag Buoys" The "Safety Marker Buoys" are installed every spring & removed in the fall by AUC VOLUNTEERS to help keep boaters away from the submerged 1912 Dam site & the "Bridge Pilings" Dive Site in Lake Minnewanka near the causeway. See the AUC's Alberta Dive Guide for further descriptions of these dive sites in Banff.
Note that the "Submerged Townsite of Minnewanka Landing" is a boat dive & does not have safety marker buoys. The boat must fly a "Dive Flag" when diving there. Live boat is recommended. DO NOT MOOR your boat to the marker.
Two Jack Lake is open for diving and the visibility isn't too bad & varies depending on local conditions. Please share the parking lot & beach area with other public users.
Scuba divers are reminded to stay clear of dams, weirs, marinas, boat channels and boat launches.
WARNING: Boat rentals are available to the public at Lake Minnewanka (and other AB Lakes) without the prerequisite of a "boating license". This means these are often very inexperienced boat operators that are even more unaware & uneducated about what the "dive flag" means!
ALWAYS use common sense & good judgement when deciding to dive or not dive - due to safety concerns, change of local conditions, your own experience & even fitness level!
DO NOT assume that the presence of the "Dive Flag" will ensure your safety! Always do controlled ascents (and descents) while diving, close to shore if possible. Use caution & common sense, be aware & don't dive in heavy boat traffic areas.