Recently, I have had many players ask me what the actual build is for my hydro tank that I use in the Ring of Fire (Perdition/Ring/Abaddon/Hell) and for farming in other areas of the game, so I thought that I'd post it here for reference. This build is extremely effective in the end-game areas, even with henchmen on board, and I used it to skill cap all my primary and secondary elites in the Ring as well. The build is based on a mesmer secondary for one skill (Arcane Echo) which is not linked to any attribute, so if you have a different secondary, replace that skill with something damaging or attribute-less if you can. I use a superior water rune and a green water staff with this build, but in the past I used a regular wand/artifact combo from the Southern Shiverpeaks collectors that gave a 20% chance for casting time reduction and a 20% chance for skill recharge reduction (which is very noticeable, especially on Maelstrom).

Minimum configuration:
One superior water rune + one major vigor rune + one minor energy storage rune.
Attribute points are maxed in water and energy storage.

Skill set:
1) Aura of Restoration
2) Water Attunement
3) Ward Against Harm (elite)
4) Ice Spear
5) Blurred Vision
6) Arcane Echo
7) Maelstrom
8) Frozen Burst

The key to this build is Ward Against Harm (elite), which gives +60 vs. fire and +24 vs. all else to everyone inside the ward, and which is in place almost all of the time. To use this with maximum effectiveness, it must be planted near the front line to include the real tanks within its protection, so I am always right in the thick of things, tanking with the rest.

In a typical encounter, I am usually the lure, so I start by either aggroing the enemies myself, or by casting Blurred Vision on a cluster of enemies just outside the aggro range. This draws them in and effectively reduces their attacks by 50%. I then throw up the ward while the real tanks start attacking. The ward has a very large radius and I try to make sure that as many allies as possible will be covered by it when it goes up. Any non-tanks inside the ward are very safe, and can usually go toe-to-toe with most attackers, especially the blurred ones, with even just a little self-healing ability. If the encounter is mild, I drop one Maelstrom on the best target or cluster of targets; if it is a challenging encounter, then I use Arcane Echo first and then drop the Maelstroms as needed.

Ice Spear is the spammable skill with no recharge time that I pack along in case I need to crank my health back up, and with a superior water rune it does high damage (sparks of the titans are particularly vulnerable to it). I'm not put off by Ice Spear's half-range, because I'm usually only using it to finish off targets near the boundaries of the ward. I use my staff for most of my attacking because it allows me to recharge my energy while doing decent damage. I recently discovered that Frozen Burst is particularly effective in the jade/mursaat areas of the Ring, especially against the bosses that like to flee, so now I always bring it along. Frozen Burst does very high damage with a superior water rune (100+), requires no targeting (making it a good "panic button"), and it also serves as a good escape route if something goes wrong because it slows everything down for a full 10 secs.

When taking out ether seals, I drop Maelstrom from the aggro distance, then run in close and throw up the ward to provide cover for the tanks from the electrical attacks of the towers. Since the ward doesn't follow me around, I can either back away from the seal's energy stripping zone and recharge, or I can stay and help take out the seal with Frozen Burst and Ice Spear until my energy is gone.

Since the critical component of this build is Ward Against Harm (elite), you must always leave yourself enough energy to replace it when it expires. This is never a problem if you're paying attention to your energy reserves. Blurred Vision can reduce the damage done to your party by 50%, allowing your healers to really focus their energies, so try to keep enough energy in reserve to renew it as well. It takes a while for non-tanks to get comfortable with the idea of a blurred jade armor or titan beating on them from inside the ward, but it really does level the playing field. Maelstrom is your primary damage-dealer and spell-stopper, so hold off from using it until you can maximize its effectiveness. It is especially good at taking out the hands and fists that spawn from risen ash hulks, so in the titan areas, be sure to keep one Maelstrom in reserve for that purpose.

If you've never played a tanking elementalist, then this is a great way to start. Try it out in Perdition or in the Desert with a hench team (bring along both healers and both tanks plus one other) and get used to the playing style. With human teams, you'll have to encourage the timid to get inside the ward and stay there; if they're skeptical, then they'll just learn the hard way that it is MUCH safer inside the ward than out. Once you're familiar with playing a hydro tank, you might find yourself leaving that static echo nuker build behind for a quite while...