Swimming

Swimming and Holding Your Breath Rules:
Other than dwarves, people on Aquaticus are used to being in the water for either fun or work, usually both. As such, swimming, holding your breath and diving to the depths are easy.

Swimming:
Under normal circumstances a person can swim for a number of minutes equal to half their constitution (round-up). After that time has passed the person will need to make a strength check starting a DC10 for an additional 5 minutes they want to swim. As additional time passes checks are made every 5 minutes with the DC rising by 1 for each additional 5 minutes that pass.

Adjustments to swimming time- If more than 50% of weight allowed is carried (total of everything) swimming time is cut in half. Thus a person with a 10 constitution could swim for 5 minutes without a strength check if they have more than 50% of their total carry weight on them. This drops to 2 ½ minutes if the person has  IF YOU HAVE MORE THAN 100% of your carry weight on you you must make strength checks every round.

Amphibious people have their swimming time halved when they exceed 50% of their carry capacity. It is halved again if they are carrying weigh up to 99% of carry capacity. If overloaded they make checks every minute.

Aquatic people, including those who can fully breath air or water are not affected.

Holding your Breath:
A surface dweller can hold his or her breath for 30 seconds for each point of constitution. Once that time passes if the person does not get a good breath of fresh air he or  she will take 1D6 nonlethal damage per round until fresh air is taken in. If a person goes zero or lower hit points they begin to drown and must make death saves at disadvantage if still underwater.

Amphibious people can hold their breath for 2 minutes per point of constitution. All other rules apply if the person does not get air in time.

Aquatic people, including those who can fully breath air or water are not affected by the amount of time underwater.