Support Gangplank, Build Guide/Options
Not all that long ago I learned about the benefit of taking the Bandit mastery from the Cunning tree on Gangplank.
Apparently it isn't exactly a new thing, but for those of you who do not know about it, I'll explain.
Bandit Gain 1 gold for each minion killed by an ally. Gain 3 gold (10 if melee) when hitting an enemy champion with a basic attack (5 second cooldown)
Gangplank is a melee champion and his Q, Parrrley, counts as a melee basic attack, and it also has a 5 second cooldown at all ranks.
This got me thinking that maybe Gangplank could be extra gold efficient as a support if you simply harass the hell out of your enemy laners with Parrrley every chance you get.
Lets look at the different support items to start
The Tribute passive seemed most appealing right away since the goal is to harass the enemy laner and this would give me between 24 and 45 gold every 30 seconds at best, +2 gold per 10 seconds. The downside I see to this passive is that it requires that I am able to get all 3 procs every 30 seconds in order to be effective. He would also benefits from the mana regeneration since using your Q every 5 seconds will start to add up. I'm actually not all that thrilled with the CDR since I really want to keep his Q on an even 5 second cooldown. CDR may be good later, but he can get that from other items.
Favor also has good synergy with the Bandit mastery since you will then gain 5 or 7 gold, as well as 5 to 10 health for every minion slain near you. I think this item would really be best if you have an ADC who is great with wave clear. In the mean time, you are still harassing the enemies to get your 10 gold. The mana regeneration helps just like with the spell thief items, but again you have some CDR to deal with.
Spoils of War is actually my favorite for this pick. I generally don't like this passive on a support because some carries don't understand that it is best to let you take cannon minions when you have this up. However, seeing as how GP has some pretty effective damage, and range from his Parrrley it can be much easier for him to utilize this. Also, the coolest thing about this to me is that he is actually able to gain the passive gold from Parrrley from last hitting the minion as well. I also really like the health that he gets from this because it makes his heal stronger as it scales on his missing health. More max health, means I can feel more comfortable about getting lower health because my heal will be more effective. However, this does not do anything for his mana concerns. The rest of our build and masteries can help with this though. Also, 
is the only support item that does not offer CDR.
As I just mentioned we will need to look at his masteries.
CUNNING The way I look at this, you NEED Bandit. So you will at least have 12 points in the Cunning tree.
Cunning Tier 1: 5 optional I generally prefer the movement speed from Wanderer on any champion because it is always useful, howerver Savagery will make your last hits on your Spoils of War empowered Parrrlay even more effective. It feels pretty bad when you miscalculate the damage and don't get the last hit.
Cunning Tier 2: 1 Secret Stash You're a support. You will probably not find yourself with red, blue, or the Rift Herald buff, so there isn't much need for Runic Affinity. You will most likely be in the bottom lane against an ADC and a support in the beginning of the match so Assassin will probably not be that helpful either. Grab a few Biscuits, a Refillable Potion, or if you want to be even more aggressive, a Corrupting Potion and sustain up.
Cunning Tier 3: 5 Meditation Mana is going to be super important for you to get the most out of your early game. I have found that even if you are running low on mana, having Meditation will give you just enough mana in a little longer than 5 seconds. While not ideal, I couldn't imagine trying this without it.
Cunning Tier 4: 1 Bandit As I have said before, this is not optional. This is pretty much the whole reason this could even work.
Cunning Tier 5 & 6: ??? Personally, I don't see much use in taking any of these. The Armor and Magic Pen from Precision may be helpful, but you probably wont need it to be useful to your team. You don't really want CDR early game, so Intellegence is not helpful. And as for the capstones. I don't expect that you will have enough burst for Stormraider's Surge, I don't really see you trading often enough for Thunderloard's Decree, and you don't have any heals or shields for your ally so *Windspeaker's Blessing would be a waste.
FEROCITY Instead I would consider how you ultimately want to play. If you want to be more of a bruiser damage support, consider placing your last 18 points into the Ferocity Tree
Ferocity Tier 1: 5 Sorcery You don't need attack speed. Despite being considered to be an auto attack, your bonus damage from Parrlay will still be enhanced by Sorcery, as well as your Barrels, and your Ultimate damage.
Ferocity Tier 2: 1 Expose Weakness Double Edged Sword is better for champions who can out trade their enemies. While you do want to harass often, you want to avoid a trade if possible. Feast could be useful if you end up going for the Spoils of War option, but even then, you will not be killing units that often unless you end up holding a lane or split pushing. Expose Weakness will help your carry trade with the enemy laner because you have continuously been harassing them.
Ferocity Tier 3: 5 optional Vampirism will be good for your own sustain early game. Personally, I would rather take Natural Talent for the free stats, and the AP will help your Scurvy be more effective.
Ferocity Tier 4: 1 Oppressor Bounty Hunter may be good because you have a global ultimate. If you manage to catch all of the enemies as they are trying to flee (and you don't get yelled at for kill stealing) you can get some pretty impressive damage. However, by slowing your enemies yourself, or relying on your allies abilities to slow your enemy, you can be a more useful damage source.
Ferocity Tier 5: 5 optional I'm going to leave this one as optional, despite my personal opinion that Battering Blows is better. You will most often be applying physical damage to your opponents, but Piercing Thoughts would be helpful with your ultimate.
Ferocity Tier 6: 1 optional Warloard's Bloodlust This would be good for sustain. Your Parrrlay is a basic attack so you can life steal with it, but your bonus damage does not count. Fervor of Battle This could honestly be the best option. Again, Parrrlay is a basic attack, and it has a 5 second cooldown. Fervor stacks have a 6 second cooldown. Parrrlay is a melee attack. Melee attacks grant 2 stacks. Could be very strong if you are able to optimize your attacks. Deathfire Touch I would actually take this for more passive damage. The fact that it applies magic damage will make it more difficult for your enemies to simply build armor and negate both you and your carry. (unless your carry deals magic damage ... but I'll talk about that later). It also doesn't require that you harass constantly like Fervor.
RESOLVE I feel like you can also be more effective as a full on tank, you can spec your remaining masteries in the Resolve tree.
Resolve Tier 1: 5 Recovery I feel that Unyielding is best on champions who have abilities that offer free armor and magic resistance stats. I would personally take Gangplank the way of the health/sustain tank and pick up Recovery for early game safety.
Resolve Tier 2: 1 Tough Skin Gangplank is not rally that much of a roaming champion, so I don't think Explorer would really be all that helpful. I did mention earlier how I like movement speed, but the fact that this is location conditional doesn't feel good to me. Tough Skin will help you to survive the situations where you attempt to harass, and get caught in a trade.
Resolve Tier 3: 5 optional I mentioned being a health/sustain tank. Both of these are great for this, however, it puts a priority on one or the other. You can either have more effective sustain from Runic Armor which includes the health recovered by Scurvy and other sustain, or you can have more flat health from Veteran Scars which will also increase the effectiveness of Scurvy when you have lower health. Of course with these options, you can always place 1/4 or 2/3 points in both.
Resolve Tier 4: 1 Perseverance Summoner spells are important and having a 10% cooldown reduction on them would be great. If you prefer that for your own personal play style, I wouldn't blame you for taking Insight, however, Perseverance would be very useful for this position.
Resolve Tier 5: 5 Swiftness Despite being "Tanky" you don't really have any built in crowd control unless you pick it up from items. Even still, being in your enemy's face does not feel good as Gangplank. Swiftness will help you to be able to avoid getting locked down. However, if you do manage to get locked down and ganged up on, Legendary Guardian would be very useful. I would consider this optional, but personally, I'm sticking with Swiftness.
Resolve Tier 6: 1 Optional I'm kind of torn with these options. Grasp of the Undying would be great, but I'm actually a little curious how often you have to deal or receive damage to be considered "in combat" Strength of the Ages is good for getting some bonus health, especially considering that you want to be taking every cannon minion in your lane. Bond of stone is probably best for protecting your carry. Damage reduction is also a great thing to have.
RUNES Most people have their own rune preferences for things like this.
I would say the most standard would be 8 AD marks and 1 crit chance Mark. >If you don't already have a critical strike chance mark in your AD rune page, I would strongly recommend it
9 mana regeneration Seals >This further helps with his mana concerns
9 magic resistance Glyphs 3 Quints of your choice. AD, Attack speed, Movement Speed, Life Steal, ...
However, I have a rune page that I think would work great I have % health Seals and Quints, but I am not completely sure if I want to keep the mana seals or not.
ITEMS
I would start with 
or 
Some time later I would want to work back to finish 
, 
, or 
depending on how the lane has been going so far.
In the mean time I will have most likely been dealing with mana issues. I would either finish up my or start to fix my mana issues by working toward 
. After this, mana is not an issue at all. The active is also a decent engage/disengage tools.
Beyond this point, you are pretty open to just about anything.
The beauty of this set up is that he should be able to afford some items that you would not normally be able to get on a support.
He can of course continue on the defensive path with 
He can be more of a bruiser with 
He could even become a secondary ADC and split push with more offensive items like 
When to pick him?
Honestly, .. this may even be a totally terrible pick in honest competitive play. This would definitely be an off meta pick for normals or just for fun with friends. It would definitely throw your enemy team for a loop though. In theory, you could take GP and a mid lane mage to the bottom lane, have the mage farm. Basically you are just rearranging the lanes and using GP as a flex split pusher.
Before anyone gets too up on their soap box about how bad this would be. I have only tried this out against Intermediate bots, and I do understand that you could beat them with literally anything. PVP is a completely different story. So at this point, it is mostly an 'on-paper' build, but I bet it would be fun, and fairly useful compared to other off-meta picks.
I think it would be great for someone (who is more skilled than me) to try it out and maybe even make a video of it.
I will most likely try it out myself sometime, but I really want to only pick it if I'm with friends. Sadly, most of the time I play PVP solo, so who knows when that will happen.