Blackstone Bay — Anchorage Guide
Overview
Blackstone Bay is one of the most visually dramatic destinations in Prince William Sound — a deep glacial fjord ringed by four active tidewater glaciers. The anchoring conditions, however, demand respect. Katabatic wind events off the Blackstone and Beloit glaciers can materialize with little warning and reach violent intensity.
Approach
From Passage Canal, head SW into the open waters of Port Wells. The bay entrance opens to the southeast. A prominent terminal moraine forms a shallow bar across the upper end of the bay — anchor before this feature, not in the glacially-turbid shallows beyond.
Anchoring
The anchorage at the head of the accessible portion of the bay is in 50–75 feet over mud and glacial silt. Holding is adequate but uneven — use a trip line. The fjord walls are too steep for stern ties.
Strong recommendation: Only anchor in Blackstone Bay in settled, calm, offshore-flow weather. Keep anchor watch. Have an exit plan before dark.
Katabatic Risk
The glaciers above discharge cold, dense air masses that pour down the fjord with little topographic obstruction. Events exceeding 60 knots inside the bay have been recorded. Visual cues: cloud wisps forming at the glacier face, sudden temperature drop, whitening water upwind of your position.
If you see these signs: weigh anchor immediately.
Wildlife
Mountain goats are commonly visible on the cliff faces bordering the glaciers. Harbor seals haul out on ice floes. Black-legged kittiwakes nest in the cliff faces. Bald eagle density is high.
Notes
- VHF relay from Whittier coast guard is marginal — plan communications before entering
- No fuel, no water, no services
- Anchoring deeper than 80ft common near glacier face — not suitable for typical rode
Add to Your Float Plan
Include Blackstone Bay as a waypoint or destination in your float plan for this trip.