initial changes

code/datums/components/nanites.dm

@@ -13,7 +13,7 @@
 
 	var/stealth = FALSE //if TRUE, does not appear on HUDs and health scans
 	var/diagnostics = TRUE //if TRUE, displays program list when scanned by nanite scanners
-	
+
 /datum/component/nanites/Initialize(amount = 100, cloud = 0)
 	if(!isliving(parent) && !istype(parent, /datum/nanite_cloud_backup))
 		return COMPONENT_INCOMPATIBLE

code/datums/elements/swimming.dm

@@ -0,0 +1,23 @@
+/// Just for marking when someone's swimming.
+/datum/element/swimming
+	element_flags = ELEMENT_DETACH
+
+/datum/element/swimming/Attach(datum/target)
+	if(!isliving(target))
+		return ELEMENT_INCOMPATIBLE
+	if((. = ..()) == ELEMENT_INCOMPATIBLE)
+		return
+	RegisterSignal(target, COMSIG_IS_SWIMMING, .proc/is_swimming)
+	RegisterSignal(target, COMSIG_MOVABLE_MOVED, .proc/check_valid)
+
+/datum/element/swimming/Detach(datum/target)
+	. = ..()
+	UnregisterSignal(target, COMSIG_IS_SWIMMING)
+
+/datum/element/swimming/proc/is_swimming()
+	return IS_SWIMMING
+
+/datum/element/swimming/proc/check_valid(datum/source)
+	var/mob/living/L = source
+	if(!istype(L.loc, /turf/open/pool))
+		source.RemoveElement(/datum/elemtn/swimming)