

Best for beginner divers, 1-8m, shore entry, mild current.
Big Arm Bay in Flathead Lake is a long, shallow pebble beach offering accessible entry for divers and snorkellers. The site features a shallow lake floor that remains at an average depth of 4 metres, with a maximum depth of 8 metres. Conditions are generally mild, with visibility ranging between 15 and 30 metres. This location is suitable for beginners and families, with typical dives lasting around 45 minutes. Facilities at the site include parking, toilets, and showers. Due to the freshwater environment, divers should be prepared for cold water temperatures, which vary significantly outside of the summer months.
47.80480, -114.31250
The park is a popular jumping-off point to Wild Horse Island.
Located 15 miles north of Polson on U.S. Highway 93 on Big Arm Bay along the west side of Flathead Lake.
Recorded at this site
Depth
Up to 8m
Visibility
15-30m
Skill Level
Beginner
Entry
Shore
Current
Mild
Typical Dive
45 min
Best Time
Jun, Jul, Aug, Sep
Yes, the site is well-suited for beginners due to its shallow pebble beach entry and mild currents.
The depth ranges from 1 to 8 metres, with an average depth of 4 metres.
Big Arm Bay is a shore entry site.
Yes, the site is suitable for snorkelling and has a snorkel rating of 3 out of 5.
The primary hazard at this freshwater site is cold water.
The best months to visit Big Arm Bay in Polson are June, July, August, and September. Conditions outside these months can still be good but are less predictable.
Big Arm Bay in Polson typically has mild currents that most divers can handle comfortably.
Visibility at Big Arm Bay in Polson typically ranges from 15 metres to 30 metres. Conditions vary with weather, tides, and seasons.