Bad Swimmer

Added a bad swimmer trait that slows you down in water and causes you to drown in deep water (depths of 2 or above).

One thing I would like to improve before merging and want advice on: Currently the splashing/"you are drowning" message spams pretty frequently and I would like to slow that down.

code/game/turfs/simulated/water.dm

@@ -73,6 +73,26 @@
 			water_breath.adjust_gas(gasid, BREATH_MOLES) // They have no oxygen, but non-zero moles and temp
 			water_breath.temperature = above_air.temperature
 			return water_breath
+	if(L && L.is_bad_swimmer() && depth >= 2 && !L.buckled())
+		L.visible_message("<span class='notice'>[L] splashes wildly.</span>","<span class='warning'>You struggle to keep your head above the water!</span>")
+		if(L.can_breathe_water())
+			var/datum/gas_mixture/water_breath = new()
+			var/datum/gas_mixture/above_air = return_air()
+			var/amount = 300
+			water_breath.adjust_gas("oxygen", amount) // Assuming water breathes just extract the oxygen directly from the water.
+			water_breath.temperature = above_air.temperature
+			return water_breath
+		else
+			var/gasid = "carbon_dioxide"
+			if(ishuman(L))
+				var/mob/living/carbon/human/H = L
+				if(H.species && H.species.exhale_type)
+					gasid = H.species.exhale_type
+			var/datum/gas_mixture/water_breath = new()
+			var/datum/gas_mixture/above_air = return_air()
+			water_breath.adjust_gas(gasid, BREATH_MOLES) // They have no oxygen, but non-zero moles and temp
+			water_breath.temperature = above_air.temperature
+			return water_breath
 	return return_air() // Otherwise their head is above the water, so get the air from the atmosphere instead.
 
 /turf/simulated/floor/water/Entered(atom/movable/AM, atom/oldloc)
@@ -125,6 +145,14 @@
 		return species.can_breathe_water()
 	return ..()
 
+/mob/living/proc/is_bad_swimmer()
+	return FALSE
+
+/mob/living/carbon/human/is_bad_swimmer()
+	if(species)
+		return species.is_bad_swimmer()
+	return ..()
+
 /mob/living/proc/check_submerged()
 	if(buckled)
 		return 0

code/modules/mob/living/carbon/human/species/species.dm

@@ -137,6 +137,7 @@
 	var/poison_type = "phoron"								// Poisonous air.
 	var/exhale_type = "carbon_dioxide"						// Exhaled gas type.
 	var/water_breather = FALSE
+	var/bad_swimmer = FALSE
 
 	var/body_temperature = 310.15							// Species will try to stabilize at this temperature. (also affects temperature processing)
 
@@ -513,6 +514,10 @@
 /datum/species/proc/can_breathe_water()
 	return water_breather
 
+// Called when standing on a water tile.
+/datum/species/proc/is_bad_swimmer()
+	return bad_swimmer
+
 // Impliments different trails for species depending on if they're wearing shoes.
 /datum/species/proc/get_move_trail(var/mob/living/carbon/human/H)
 	if( H.shoes || ( H.wear_suit && (H.wear_suit.body_parts_covered & FEET) ) )

code/modules/mob/living/carbon/human/species/station/traits_vr/negative.dm

@@ -168,3 +168,9 @@
 	custom_only = FALSE
 	varchange_type = TRAIT_VARCHANGE_MORE_BETTER
 
+/datum/trait/negative/bad_swimmer
+	name = "Bad Swimmer"
+	desc = "You can't swim very well, all water slows you down a lot and you drown in deep water."
+	cost = -1
+	custom_only = FALSE
+	var_changes = list("bad_swimmer" = 1, "water_movement" = 4)