Underwater combat confusion

Hello All,

I've got a question, or rather ask for clarification from wise fellow Pathfinders!

If I understand rules correctly, firm footing underwater is much more beneficial than usage of Swim skill? Is it intentional or it's just a fumble of RAW?

If it's not, then I just can't understand why deep bog (4 feet of water) reduces speed by 1/4 and total submersion only by 1/2. Maybe there is an errata or something? If there is no errata - please advice me, what is considered correct by community?

Another thing that bothers me. Swim speed of ordinary human - 15 feet per 6 seconds. It is awfully slow, you know... Am I only one person that is bothered by this? :)
I'm considering allowing to take -5 penalty to double Swim speed as with Climb.

Well it's slow but well, this is not a simulationist rpg, it isn't trying to copy real life for all situations.

In general I'm not bothered by it. I follow the rule of the adventurer:

Never go underwater. If your DM wants you underwater, it's to throw all the weird aquatic monsters that he never get to use at you.

But anyway when I have to go underwater...I come with my freedom of movement to avoid all that nonsense about movements.

Alright, so we need to start with an important premise that affects almost all of these. "Underwater combat is designed around a bunch of surface dwelling only humanoids trying to fight underwater."

Firm footing is more important than good swimming because the humanoid fighting is used to gravity anchoring them to the ground and all of their combat moves are designed assuming their legs and arms can be stationary, if they so choose. The motions of swimming and the motions of swinging a sword may be compatible at times but that doesn't mean the combatant can choose to make them that way. It'd be luck (represented by a good roll).

A deep bog costs 4 squares of movement to move into. A swim check allows you to move at 1/4 your speed. These are for single move actions. While not quite identical, they mean the same thing for a creature with a 40 foot movement speed. They are different because in a deep bog you are assumed to be walking on the bottom and the slowdown is not from the water but from the muck. You can also swim in a deep bog and ignore the deep bog modifiers to movement.

Swim speed is absolutely low. For one thing, being trained in swim should allow you to swim faster. For another, swimming is ridiculously easy for humans. Babies can do it (mammalian diving reflex). The infirm and elderly (low strength) can do it with almost no training. The primary training for beginning swimmers is overcoming the fear of water, not what motions to make to stay up. On the flip side of this is that: you can swim carrying a grand piano pretty easy even with the appropriate penalties, an average 10 Con person can hold their breath for 2 minutes (try it on your family), if you can hit DC 20 Swim you can swim indefinitely, everyone can swim for an hour straight before they'll ever be fatigued.

If you're looking for houserules I would agree with -5 to double and suggest -10 or 15 to double again (so a trained swimmer can swim at full speed) and reducing the DC for calm water to 5 (or even 0).