The Double Broadside mode (first cannon shot award) is very valuable. Shots to broadside start at 1M and double each shot up to 32M for 30s.
During the Walk the Plank video mode, the flipper buttons also swim. You can probably swim faster using those instead of the fire button.
If the ball doesn't hit a single switch after plunging you can let the ball drain for a free ball save. There is no limit to how many of these you can get -- it doesn't count as your one proper "ball save".
Shoot the Whirlpool ramp five times in a row for an Extra Ball. Various video modes may also awards an Extra Ball.
MB can be set on easy to hard. On hard mode the ramps alternate flashing (starting with the left ramp) to give one SINK SHIP letter.
During quick multiball, short plunge, then shoot the lock before hitting a switch, then shoot second ball from cannon in too for easy 3 ball
Completing all 'modes' lights Jackpot, 30 million in tournament mode. With each mode being ~3mil+ with hurryup, can be viable strategy
During cannon shots, ball can be rebounded across multiple target banks for extra letters
Sinking ships is primary goal. Light (and stack) SINK SHIP from MB or cannon shots to lit shots. Load cannon under ramp and shoot broadside.
Shoot the cannon to sink ship if lit, but otherwise don't always shoot up middle. Shoot flashing shots to spot letters and get awards.
Spot L-O-C-K letters from inlanes or left Pirate Cove shot. Shoot Pirate Cove for MB. Lock both balls into the Pirate Cove for 3-ball MB.
All ramps in MB spot SINK SHIP letters. Completing SINK SHIP opens the upper ramp for a cannon shot. In 3-ball MB ramps spot 2 letters.
Immediately after hitting the skillshot you can let the ball drain. Assuming it does so quickly enough, you'll get a ball save. You can then easily plunge into Davey Jones Locker, which was opened by the skillshot.
Plunge into the yellow bank of Torch standup targets for 500K and to open the upper left ramp to load cannon.
During a "Polly says" after hitting broadside, mash both flippers for a Polly Killed 2M bonus.