Before I go on with the analysis, I'm posting this here because my experience with this set is in the OU metagame, and I do actually think that this set has the most potential in the OU since there are far fewer Grass types in the OU as opposed to the UU. This set along with Dual Screen Magnezone has won me some matches, and I have saved some battles if anyone is curious to see some examples of this set being used effectively. Gyarados is usually cited as the Pokemon that outclasses Gatr, but on my team, I've been using BOTH this Gatr and Subbounce Gyarados, and I've found Gatr considerably more effective at getting in and setting up for a lategame sweep.
http://www.smogon.com/dp/pokemon/feraligatr
[SET]
Name: Aqua Jet
Move 1: Aqua Jet
Move 2: Swords Dance
Move 3: Return/Dragon Claw
Move 4: Substitute/Waterfall
Item: Leftovers/Muscle Band/Mystic Water
Nature: Adamant
EVs: 252 HP, 252 attack, 4 SpD
[Set Comments]
<p>With the advent of HGSS, Feraligatr has yet another option available that distinguishes it from Gyarados. Aqua Jet is used in conjunction with Swords Dance on this set to bypass Feraligatr's mediocre speed and make it a formidable mid to late game sweeper.</p>
<p>Using this set is fairly straightforward. As speed is not a top priority for this Pokemon, EVs are invested into HP to provide some extra general durability. Thanks to Feraligatr's respectable bulk and lack of a 4x weakness compared to its Flying counterpart Gyarados, it shouldn't be too hard to find an opportunity to switch in Feraligatr safely, Swords Dance, and start pummeling your opponent with STAB Aqua Jets. If your opponent switches, it may be in fact possible for Feraligatr to get two Swords Dances depending on what their counter is.</p>
<p>Return is chosen as the primary option for your second attack, as only Empoleon, Shedinja, and Dialga resist the combination of Water/Normal coverage. Factoring Intimidate, Swords Dance boosted Return does 57.7% minimum to Offensive Dragon Dance Gyarados, a guaranteed 2HKO even factoring possible Leftovers recovery. Dragon Claw may be considered over Return for scoring a super effective hit on Dragons who resist Aqua Jet, usually OHKOing offensive versions of Salamence and Dragonite after boosted by Swords Dance especially if Stealth Rock is in play. It is worth noting that with Stealth Rock in play, using Return + Torrent boosted Aqua Jet also KOs most Salamence (factoring Intimidate) and Dragonite after one Swords Dance.</p>
Timid Life Orb Gengar for instance only does 83.4-98.9% maximum damage to this Feraligatr with Thunderbolt, which means you have a 67% chance of surviving the attack if you switch into Stealth Rock, gain a turn of leftovers recovery as they switch to Gengar, and then attack you. At this point you may have amassed two Swords Dances, while Feraligatr is capable of OHKOing Gengar with a 2+ Aqua Jet boosted by Torrent (which does the same damage as a 4+ Aqua Jet without the Torrent boost). Timid Jolteon is also slain by 2+ Aqua Jet boosted by Torrent, but you have to be wary that Jolteon using Specs or Life Orb have a guaranteed 1HKO with Thunderbolt.
<p>This set works best when provided with Dual Screen support, which Magnezone can provide, and it is through Dual Screens that Feraligatr best distinguishes itself from Gyarados. Unlike Gyarados, he doesn't have a 4x weakness to Electric moves, and instead of a (Stealth) Rock weakness, he has a less common Grass weakness, and since this set doesn't care nearly as much about speed as other sets without Aqua Jet, durability can get more attention. With an HP investment, this Feraligatr is only slightly less bulky than Gyarados on the special spectrum, but takes hits from Thunderbolt considerably better. Timid Specs Jolteon still OHKOs Offensive Dragon Dance Gyarados even with Dual Screens active, while this Feraligatr survives under Dual Screens with around 24.25-35.85% health. Factoring Stealth Rock and Leftovers recovery, this puts you in Torrent range and allows a guaranteed OHKO with a 2+ Aqua Jet. Assuming that your opponent lacks very powerful super effective attacks to threaten you, or that they need to switch in order to bring in a counter to this set, Feraligatr should have fairly little trouble amassing two or even three Swords Dances.</p>
<p>Leftovers is the preferred item on this set to provide more leeway to use Substitute freely and provide overall more bulk and thus more opportunities to use Swords Dance, especially if Sandstorm (or Hail) is active and chipping away at your health. You definitely don't want the chip damage from weather ruining your Torrent boosted 6+ Aqua Jet sweep. Muscle Band or Mystic Water however are decent item choices if the weather and/or extra durability are not a big problem for you and may very well be worth consideration especially on a Rain team, where a +4 Aqua Jet boosted by both Torrent and Mystic Water has a slight chance of OHKOing a full health Skarmory under the rain.</p>
<p>This set will encounter some problems against bulky users of Roar/Whirlwind that do not get 1HKOed by your boosted attacks, so it is in your best interest to have these opponents weakened or removed to ensure that they do not stop your sweep. Under normal weather conditions, Skarmory for example is only 3HKOed by 2+ Aqua Jet boosted by Torrent, and even a 6+ Torrent Boosted Aqua Jet only manages 78.1% maximum damage on the Spiker set. Physically Defensive Zapdos takes 93.2 max damage from a 6+ Torrent Aqua Jet or 89.6% - 105.5% from Return, which requires Stealth Rock to secure a reliable 1HKO.</p>
http://www.smogon.com/dp/pokemon/feraligatr
[SET]
Name: Aqua Jet
Move 1: Aqua Jet
Move 2: Swords Dance
Move 3: Return/Dragon Claw
Move 4: Substitute/Waterfall
Item: Leftovers/Muscle Band/Mystic Water
Nature: Adamant
EVs: 252 HP, 252 attack, 4 SpD
[Set Comments]
<p>With the advent of HGSS, Feraligatr has yet another option available that distinguishes it from Gyarados. Aqua Jet is used in conjunction with Swords Dance on this set to bypass Feraligatr's mediocre speed and make it a formidable mid to late game sweeper.</p>
<p>Using this set is fairly straightforward. As speed is not a top priority for this Pokemon, EVs are invested into HP to provide some extra general durability. Thanks to Feraligatr's respectable bulk and lack of a 4x weakness compared to its Flying counterpart Gyarados, it shouldn't be too hard to find an opportunity to switch in Feraligatr safely, Swords Dance, and start pummeling your opponent with STAB Aqua Jets. If your opponent switches, it may be in fact possible for Feraligatr to get two Swords Dances depending on what their counter is.</p>
<p>Return is chosen as the primary option for your second attack, as only Empoleon, Shedinja, and Dialga resist the combination of Water/Normal coverage. Factoring Intimidate, Swords Dance boosted Return does 57.7% minimum to Offensive Dragon Dance Gyarados, a guaranteed 2HKO even factoring possible Leftovers recovery. Dragon Claw may be considered over Return for scoring a super effective hit on Dragons who resist Aqua Jet, usually OHKOing offensive versions of Salamence and Dragonite after boosted by Swords Dance especially if Stealth Rock is in play. It is worth noting that with Stealth Rock in play, using Return + Torrent boosted Aqua Jet also KOs most Salamence (factoring Intimidate) and Dragonite after one Swords Dance.</p>
Timid Life Orb Gengar for instance only does 83.4-98.9% maximum damage to this Feraligatr with Thunderbolt, which means you have a 67% chance of surviving the attack if you switch into Stealth Rock, gain a turn of leftovers recovery as they switch to Gengar, and then attack you. At this point you may have amassed two Swords Dances, while Feraligatr is capable of OHKOing Gengar with a 2+ Aqua Jet boosted by Torrent (which does the same damage as a 4+ Aqua Jet without the Torrent boost). Timid Jolteon is also slain by 2+ Aqua Jet boosted by Torrent, but you have to be wary that Jolteon using Specs or Life Orb have a guaranteed 1HKO with Thunderbolt.
<p>This set works best when provided with Dual Screen support, which Magnezone can provide, and it is through Dual Screens that Feraligatr best distinguishes itself from Gyarados. Unlike Gyarados, he doesn't have a 4x weakness to Electric moves, and instead of a (Stealth) Rock weakness, he has a less common Grass weakness, and since this set doesn't care nearly as much about speed as other sets without Aqua Jet, durability can get more attention. With an HP investment, this Feraligatr is only slightly less bulky than Gyarados on the special spectrum, but takes hits from Thunderbolt considerably better. Timid Specs Jolteon still OHKOs Offensive Dragon Dance Gyarados even with Dual Screens active, while this Feraligatr survives under Dual Screens with around 24.25-35.85% health. Factoring Stealth Rock and Leftovers recovery, this puts you in Torrent range and allows a guaranteed OHKO with a 2+ Aqua Jet. Assuming that your opponent lacks very powerful super effective attacks to threaten you, or that they need to switch in order to bring in a counter to this set, Feraligatr should have fairly little trouble amassing two or even three Swords Dances.</p>
<p>Leftovers is the preferred item on this set to provide more leeway to use Substitute freely and provide overall more bulk and thus more opportunities to use Swords Dance, especially if Sandstorm (or Hail) is active and chipping away at your health. You definitely don't want the chip damage from weather ruining your Torrent boosted 6+ Aqua Jet sweep. Muscle Band or Mystic Water however are decent item choices if the weather and/or extra durability are not a big problem for you and may very well be worth consideration especially on a Rain team, where a +4 Aqua Jet boosted by both Torrent and Mystic Water has a slight chance of OHKOing a full health Skarmory under the rain.</p>
<p>This set will encounter some problems against bulky users of Roar/Whirlwind that do not get 1HKOed by your boosted attacks, so it is in your best interest to have these opponents weakened or removed to ensure that they do not stop your sweep. Under normal weather conditions, Skarmory for example is only 3HKOed by 2+ Aqua Jet boosted by Torrent, and even a 6+ Torrent Boosted Aqua Jet only manages 78.1% maximum damage on the Spiker set. Physically Defensive Zapdos takes 93.2 max damage from a 6+ Torrent Aqua Jet or 89.6% - 105.5% from Return, which requires Stealth Rock to secure a reliable 1HKO.</p>