You can finish Quarry in 32 panels (34 including boat):

• First, snipe the stairs shortcut from Shadows
• Next, solve Mill normally (rows 1, 2, control panel). Don't take the stairs to leave, just raise the ramp in the control room.
• Solve Boathouse 1-5 from the dock
• Solve Boathouse 6/7 from the boat, should be just beyond the dock
• Solve Boathouse 8 with a moving boat on slowest speed (this is really hard, expect to fail it)
• Solve Boathouse 9 from the log pile
• Solve Boathouse 10, 11 from Shadows
• Solve Boathouse 12 from Boathouse again

Video for reference: