Down with the ship

Rumours pass from mouth to mouth in this coastal town
They say there's something in the ocean dragging our ships down
They say that boats going out have not been returning
Although the lighthouse keeper keeps his fire burning
The fleet is depleted, so supplies run low
Wives run out to the harbour begging husbands not to go
People lose their scruples, turn to contraband
And every morning they find more blood on the sand

Sharpen your cutlass, test your guns
You're married to the ocean from now on
Arm the cannons, and load the horses
When this ship goes down, it won't be natural causes

As the ship sails south, the mood is defiant
The crew long for a chance to take down a giant
The timbers are sturdy and the men are tough
But if the air is still, why is the water so rough?

Though the water roars, there's no wind today
The sail fails to flutter, no chance to get away
As a dozen massive tentacles emerge from the waves
It looks like this crew is headed for a watery grave
Harpoons do nothing, cannons don't impress
No amount of gunpowder can free us from this mess
Take the lifeboats, cross your fingers, this will be our last trip
What kind of captain doesn't go down with his ship?