Simulate towing Victorian houses, floating homes, and oversized architectural structures across San Pablo Bay. Evaluate tidal clearance windows, under-keel depths, air drafts, and required bollard pull against crosswinds.
Historic multi-story houses present enormous bluff-body surface areas (1,200–2,800 sq ft). With an aerodynamic drag coefficient $C_w \approx 1.25$ to $1.4$, even a 20-knot San Francisco Bay summer breeze generates over 7.5 tons of lateral force, requiring dedicated assist tugs to counter leeway drift.
San Pablo Bay features expansive shallow flats averaging only 4–8 ft at MLLW outside the dredged pin-straight shipping channel. High spring tides (+5.5 ft) provide a narrow 3.5-hour operating window to navigate out of creeks and sloughs without grounding the loaded barge.
Towing structures over 30 ft on high deck barges risks collision with highway bridge spans (Richmond-San Rafael, Carquinez) and overhead high-voltage transmission lines. Air draft must be calculated at High Water slack to verify vertical clearance.