LAST V1.0.0.120:

Grog Soaked Blade Grog Soaked Blade:
It will now apply a 7% slow instead of reducing healing and regeneration. The slow stacks up to 5 times.
Duration reduced to 3 seconds from 10.
Poison magic damage changed to 4-21 per second from 5-19 ( 5 + (1 x level)).
Parrrley Parrrley:
Now applies Grog Soaked Blade Grog Soaked Blade to the target hit.
Fixed a bug where it could sometimes restore gold to other players.
Raise Morale Raise Morale: active duration increased to 7 seconds from 6.
Cannon Barrage Cannon Barrage: base damage per cannonball increased to 75/120/165 from 65/110/155.

V1.0.0.118:

Stats:
Armor per level increased to 3.3 from 2.8.
Attack speed per level increased to 2.75 from 2.35.
Attack range increased to 125 from 100.
Remove Scurvy Remove Scurvy: cooldown reduced to 22/21/20/19/18 from 30/27/24/21/18.
Cannon Barrage Cannon Barrage:
Slow increased to 25% from 15/20/25%.
Cooldown reduced to 120/115/110 from 120.

V1.0.0.100:

Fixed a display error with Grog Soaked Blade Grog Soaked Blade and death recap.
Fixed a bug where Gangplank's passive would be replaced with the Grog Soaked Blade Grog Soaked Blade debuff text when struck by another Gangplank.

V1.0.0.94:

Parrrley Parrrley:
Bonus damage reduced to 100% from 110%.
It is no longer dodgable and is unaffected by blinds.
Raise Morale Raise Morale now grants 8/12/16/20/24 attack damage instead of 12-36% attack speed.
Cannon Barrage Cannon Barrage:
Cannonball damage reduced to 100/140/180 from 140/200/260.
Cannonball radius increased to 275 from 225.
Slow amount reduced to 35%/45/55 from 40/50/60.

V1.0.0.86:

Parrrley Parrrley gold gain increased to 4/7/10/13/16 from 3/5/7/9/11.

V1.0.0.85:

Added "Yarr! I'm a mighty Pirate!" buff.

V1.0.0.82:

Tweaked autoattack animation timing.

V1.0.0.74:

Parrrley Parrrley:
It now deals Physical Damage.
Fixed a bug in which Parrrley Parrrley was dealing extra damage.
Percentage damage from Attack Damage increased to 110% from 80%.
Bonus damage reduced to 20/55/90/120/150 from 30/60/90/120/150.
It will no longer apply Grog Soaked Blade Grog Soaked Blade.
Fixed a tooltip issue with Grog Soaked Blade Grog Soaked Blade.

V1.0.0.72:

Parrrley Parrrley now applies Grog Soaked Blade Grog Soaked Blade.

V1.0.0.63:

Cannon Barrage Cannon Barrage no longer reveals Gangplank to enemies when cast.
Fixed a bug where Cannon Barrage Cannon Barrage's particles showed above the fog of war, even if you didn't have vision of the area.
Fixed a bug where Gangplank would fail to close distance to cast Parrrley Parrrley or Raise Morale Raise Morale if Cannon Barrage Cannon Barrage was occurring.

V1.0.0.61:

Cannon Barrage Cannon Barrage:
Slow % reduced to 40/50/60 from 40/55/70.
Damage reduced to 140/200/260 from 160/220/280.
Grog Soaked Blade Grog Soaked Blade:
Healing reduction effect increased to 65% from 50%.
Duration increased to 10 seconds from 8.

V0.9.25.34:

Parrrley Parrrley:
Damage reduced to 30/60/90/120/150 from 40/80/120/160/200.
Ability scaling with attack damage increased to 0.8 from 0.65.

V0.9.25.24:

Stats:
Base Armor lowered to 20 from 22.
Armor per Level increased to 2.8 from 2.2.
Base Crit lowered to 3 from 3.7.
Magic Resist per Level increased to 1.25 from 0.
Cannon Barrage Cannon Barrage:
Damage per Cannonball increased to 160/220/280 from 150/200/250.
Slow increased to 40/55/70 from 40/50/60.

V0.9.25.21:

Stats:
Added Missing Mana Regeneration per Level.
Move Speed increased to 315 from 310.
Parrrley Parrrley:
Weapon Damage reduced to 95% from 100%.
Base Damage Increased to 40/80/120/160/200 from 20/40/60/80/100.
Grog Soaked Blade Grog Soaked Blade:
Duration Increased to 7 from 3.
Damage Reduced to 5 + (1 per level) from 10 + (1 per level).
Cannon Barrage Cannon Barrage:
Altered Implementation to make it less random and more uniform around the circle.

V0.9.22.16:

Raise Morale Raise Morale:
Cooldown reduced to 25 from 30.
Activating this skill no longer removes Morale Boost from himself (he now gets double effect for the duration).
Movement Speed Bonus reduced to 2/4/6/8/10% from 4/6/8/10/12%.
Remove Scurvy Remove Scurvy:
Ability Power Ratio increased to 1 from .3.
Mana Cost modified to 65 from 55/60/65/70/75.
Cooldown modified to 30/27/24/21/18 from 20.
Cast Time reduced to make it a quicker cast.

V0.9.22.15: Added.

Parrrley Parrrley: Pirate shoots a target unit dealing Physical Damage, if he kills it then he gains extra gold. Physical Damage abilities deal your champion's Attack Damage and can trigger on hit effects in addition to the ability's effects.
Remove Scurvy Remove Scurvy: Consumes a large quantity of citrus fruit which clears any crowd control effects on him and heals him.
Raise Morale Raise Morale:
Passive: Gangplank's Attack Speed and Movement Speed is increased. Gangplank doesn't receive the benefit of the passive while the spell is recharging.
Active: Gangplank kills an allied minion, inspiring nearby champions to receive Raise Morale's passive benefits for 10 seconds.
Cannon Barrage Cannon Barrage (Ultimate): Gangplank signals his ship to fire upon an area for 10 seconds. Each cannon ball deals damage and slows enemy units by 40% for 1.5 seconds.
Grog Soaked Blade Grog Soaked Blade (Innate): Gangplank's attacks apply a poison that deals 5 damage (+1 dmg per level) a second for 7 seconds and reduces incoming healing by 40%.