The well-established Inside Passage from Seattle, North by Northwest through Southeastern Alaska is familiar to Jupiter and her crew. Yet the immense wilderness of archipelagos and shorelines remains awash in ancient arcanum and concealed, often impractical, diversions and distractions.

The Seymour-Belize Inlet Complex, which sounds like a medical disorder, is a reticulation of channels hidden-in-plain-sight south of Cape Caution, which attracts Jupiter’s attention. The crew, now including Katie, a mirific niece keen for an adventure, crosses a billowy Queen Charlotte Strait to stage the approach from Alison Harbour.

Jupiter’s tortuous crossing to Alison Harbour involves every stabilization contrivance and considerable endurance.

A dense bloom of moon jellies swarms in Alison Harbour, threatening Jupiter’s raw water intakes.

The reliable Douglas cruising guide commits only a few of its 400 pages to hundreds of miles of navigable glacier-carved fjords, inviting explorers to “Access the Cruising Wonderland Beyond Nakwakto Rapids,” and paragraphs that describe adrenaline pumping experiences crossing the world’s fastest rapids running to 16 knots, and cautions in italics warning of seething waters, a mid-channel island that “trembles” in the flow, and strategies to avoid types of turbulence, overfalls, whirlpools and other menaces.

The Nakwakto rapids, the world’s fastest navigable cascade that no one has ever heard of, deters entry into an extensive complex of parallel channels beyond. A Current Chart predicts the times of maximum and minimum water flow.

Little wonder that few recreational vessels attempt the nasty Nakwakto.

The Nakwakto, however, can reliably be crossed at slack tide, when boats like ours have a few minutes to enter or exit a magnificent mountainous region of seldom traveled waterways.

Jupiter crosses the rapids at slack water passing Turret Rock dubbed Tremble Rock because lore describes it quaking in the washy tempest.

The roiling waters of the rapids create a rich habitat for marine life. Cormorants roost along the rock walls waiting to dive’n dine.

Turret Rock, occupying the center of the Nakwakto fairway, acts as an imperfect stopper parting the flow of water through the narrows, and adding a geographic hazard to an already problematic passage. Mariners occasionally post signs on trees here to prove that they have dared the transit. Tidal range within the watershed is so restricted by this aqueous chokepoint that tides in the fjords up stream of the bottleneck are only a third the height of those outside in Queen Charlotte Strait.

During our visit, Treadwell Bay, in Pacific waters sees a tidal range of 8 feet, whereas at Johnson Point, within the inlet it is less than 3 feet.

Entering the immense watershed of deep channels and fjords of Seymour and Belize Narrows, Jupiter finds 5 days of passages and anchorages of beauty and interest with no neighbors, other than one commercial prawn fisherman.

A lone commercial fishing vessel works the inlets, and a vintage floathouse is the only habitation seen.

Enough lake-fed waterfalls and cascades reach the sea to create brackish water, stained brown by forest tannins.

Several waterfalls along the fjords can be approached within a few feet owing to great depths near the shoreline.

The weather is bright, but busted by fastigiate mountain geography, interrupting or accelerating prevailing airflow, inducing unpredictable upslope and downslope winds known as Williwaws. Jupiter rides calmly on anchor at night, but daytime is full of surprises.

Anchorages can be deep and often steep right to the shoreline requiring inventive anchoring strategies.

Many patches of mountainside woodlands are being serially logged, although we catch no one in the act.

Anchorages that invite reflection are found near river outflows and cliffsides.

Exploring an enigmatic place entails imagination, preparation and patience. It wants the time and the temperament to initiate a diversion with an uncertain outcome. Imagination gets you there, reality gets you back again.