Health Maxing by Training Underwater

There was a post a couple of days ago about gaining END. While trying to get to 800 HP on my character I always noticed the swimming skill gives END but its not efficient to just walk in water tiles all day. Then I remembered training on target dummies passes time.

Blessed with this knowledge I started training on dummies while underwater.

Simply create a water tile with at least 3 depth - and train on the dummy while on the water tile. You can't have a breathing underwater mod on any of your gear to train swimming and whenever the suffocate the training will end, so just walk 3 spaces to start training again.

If you're specifically targeting END you can equip a mace, staff or polearm, or just use your weapon of choice and get free END while training.

As your swimming increases you will be able to last longer underwater allowing you to train more before having to reset.

Update - It also works with gallows and doesn't require you to stop when suffocating, but you have to heal yourself before leaving or you will die from suffocation.