More stuff, finalizes it I hope.

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

@@ -457,7 +457,7 @@
 /mob/living/carbon/proc/should_have_organ(var/organ_check)
 	return 0
 
-/mob/living/carbon/proc/can_feel_pain(var/check_organ)
+/mob/living/carbon/can_feel_pain(var/check_organ)
 	if(isSynthetic())
 		return 0
 	return !(species.flags & NO_PAIN)

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

@@ -305,3 +305,7 @@
 // Called in life() when the mob has no client.
 /datum/species/proc/handle_npc(var/mob/living/carbon/human/H)
 	return
+
+// Called when lying down on a water tile.
+/datum/species/proc/can_breathe_water()
+	return FALSE

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

@@ -193,6 +193,9 @@
 		BP_R_FOOT = list("path" = /obj/item/organ/external/foot/right)
 		)
 
+/datum/species/skrell/can_breathe_water()
+	return TRUE
+
 /datum/species/diona
 	name = "Diona"
 	name_plural = "Dionaea"

code/modules/mob/living/living.dm

@@ -796,3 +796,7 @@ default behaviour is:
 /mob/living/proc/update_water() // Involves overlays for humans.  Maybe we'll get submerged sprites for borgs in the future?
 	return
 
+/mob/living/proc/can_feel_pain(var/check_organ)
+	if(isSynthetic())
+		return FALSE
+	return TRUE