I was out sailing recently, and there was someone else who kept sinking a Colossus in a single broadside. I decided to try and figure out how he did that, and after i quickly retrained my skills, i was able to do it easily and every time. Heres how:

Skills Needed

• I have maxed sailing*
• I have maxed round shot
• I have maxed barrage
• I have maxed broadsides
• You need open fire on, but don't need to max it
• Use a War Frigate or War Galleon
• Cannon rams may help, but are not necessary

*I'm not sure if this is required, but it helps for sure. The same is probably true with cannon.

If this is done correctly, each round shot should do about 1000 damage. Each shot must hit for this to work. Hope this works for you as well as it did for me!

:-) :-) :-) :-) :-) :-) :-) :-) :-) :-)