best way to level up swimming?
 

playing a bard, can i just swim against a wall underwater with enduring breath to level it up?

With experimentation, it doesn't seem to work, but is leveling up swimming so random that I'm not giving it enough time? Or do I actively need to be going in a direction to level it up?

I believe you need to be moving, I just set myself swimming in a circle and afk a few hours

Pro tip: there are some BFG planks still spawning in Iceclad underwater. The spawn point is completely random, so just keep swimming round trying to find one and you’ll cap out in no time.

Should be obvious I think... you swim.

It takes nearly a full day of constant movement in water to max out swimming, the skill ups come very slow at the higher levels but its worth it, max swimming is like having SoW on underwater.

My favorite place as a bard is in Cobalt Scar, there is a rock that sticks out of the zonewall between SG entrance and the Beach that has a downward slope. You can put on selo's song of travel, set your view to facing max up, and set auto run to on. The downward slope will ensure your legs are always in the water and it was much faster skill ups than anything else I could find without any user inputs needed.

Other pro tips:
Anytime you're in a zone with water you can run along the shore, if your feet are in the water, even if you're still running and not swimming you will get skill ups. I "trace" the shore in zones like lake of ill omen and innothul swamp to add a couple of skill ups each time I run through.

Running on the ice river in Everfrost skills up your swimming so another good spot you could auto run into a wall and get skill ups. There is also a pavilion in Lake of Ill Omen in the lake that has a floor you can run on but is in the water, you can auto run directly into one of the 4 pillars.

There seems to be a component of distance (or potential distance) covered along with presumably an RNG check to give a skill up. So I find the faster you are moving (i.e. sow speed+) the faster the skill ups will come, that's why I recommend a strategy that involves running skill ups as opposed to being fully submerged.

EDIT: to be clear, you don't need to be actually moving (changing location) to skill up. Auto running into a wall/object without location change does result in skill ups.

Fishbone Earring or any other EB item + dumbbell pressing down 'up' and 'left' button on your keyboard

Go into third person mode, hold page up or whatever your chosen hotkey is until you move upward when you swim. You want to angle up enough to not sink/drown, not enough that you start to jump out of the water. Next turn on autorun, and hold a directional key so that your character spins, and then tab out. If you tab out while swimming upwards and spinning with a directional key (not mouse), your character will continue to swim in a circle.

Hope this helps.

Also - you can tab back in after you do the above, tabbing out just locks the directional input which is the important part. Your character will continue to swim in circles as long as you don't hit another movement key.

IIRC swimming is capped based on level now, so increases only occur in increments unless you're of a higher level and neglected swimming. That's been my experience on low level alts at least, number doesn't go up beyond a certain point until gaining additional levels.