diff --git a/landgen.cpp b/landgen.cpp
index 69b7428b..8baa94d4 100644
--- a/landgen.cpp
+++ b/landgen.cpp
@@ -155,18 +155,18 @@ EX eMonster emerald_monster() {
 
 EX void build_pool(cell *c, bool with_boat) {
   bool vacant = true;
-  if(c->monst || !among(c->wall, waNone, waSea, waBoat)) vacant = false;
-  forCellCM(c1, c) if(!among(c1->land, laNone, laVariant) || c1->monst || !among(c1->wall, waNone, waSea, waBoat)) vacant = false;
+  if(c->monst || !among(c->wall, waNone, waDeepWater, waBoat)) vacant = false;
+  forCellCM(c1, c) if(!among(c1->land, laNone, laVariant) || c1->monst || !among(c1->wall, waNone, waDeepWater, waBoat)) vacant = false;
   if(vacant) {
-    c->wall = waSea;
-    forCellEx(c1, c) if(c1->wall != waBoat) c1->wall = waSea;
+    c->wall = waDeepWater;
+    forCellEx(c1, c) if(c1->wall != waBoat) c1->wall = waDeepWater;
     if(with_boat) c->move(hrand(c->type))->wall = waBoat;
     }  
   }
 
 EX void place_elemental_wall(cell *c) {
   if(c->land == laEFire) c->wall = waEternalFire;
-  else if(c->land == laEWater) c->wall = waSea;
+  else if(c->land == laEWater) c->wall = waDeepWater;
   else if(c->land == laEAir) c->wall = waChasm;
   else if(c->land == laEEarth) c->wall = waStone;
   }
@@ -1747,8 +1747,8 @@ EX void giantLandSwitch(cell *c, int d, cell *from) {
           if(tf == tfRear) c->wall = waStone;
           // broad tail and desaturated shell helps with water
           PSH(tfTail, tfShellSat)
-          if(tf == tfTail) c->wall = waSea;
-          if(tf == tfShellSat) c->wall = waSea;
+          if(tf == tfTail) c->wall = waDeepWater;
+          if(tf == tfShellSat) c->wall = waDeepWater;
           #undef PSH
           }
         }
@@ -2376,7 +2376,7 @@ EX void giantLandSwitch(cell *c, int d, cell *from) {
           c->monst = elof;
           if(c->land != laEAir) chasmifyElemental(c);
           c->wall = waNone;
-          if(c->land == laEWater) c->wall = waSea;
+          if(c->land == laEWater) c->wall = waDeepWater;
           }
         else if(hrand(5000) < 100 + elkills*3 && notDippingFor(itElemental))
           c->item = localshard;
@@ -2476,7 +2476,7 @@ EX void giantLandSwitch(cell *c, int d, cell *from) {
           c->item = itVarTreasure;
         }
       if(d == 7 && c->wall == waTrapdoor) {
-        forCellEx(c1, c) if(among(c1->wall, waSea, waBoat))
+        forCellEx(c1, c) if(among(c1->wall, waDeepWater, waBoat))
           c->wall = waNone;
         }
       break;
diff --git a/mapeffects.cpp b/mapeffects.cpp
index c06e2253..1a2872cb 100644
--- a/mapeffects.cpp
+++ b/mapeffects.cpp
@@ -296,7 +296,7 @@ EX bool snakepile(cell *c, eMonster m) {
   else if((c->wall == waSea && c->land == laLivefjord))
     c->wall = waNone;
   else if((c->wall == waSea && isWarpedType(c->land)))
-    c->wall = waNone;
+    c->wall = waShallow;
   else if(isGravityLand(c->land)) {
     if(m == moHexSnake)
       c->wall = waPlatform;
@@ -325,9 +325,12 @@ EX bool snakepile(cell *c, eMonster m) {
     if(m == moDarkTroll) c->wall = waDeadwall;
     }
   else if(c->wall == waCavefloor) c->wall = waCavewall;
-  else if(c->wall == waSea && c->land == laCaribbean) c->wall = waCIsland;
+  else if(c->wall == waSea && c->land == laCaribbean) c->wall = waShallow;
   else if(c->wall == waSea && c->land == laWhirlpool) return false;
-  else if(c->wall == waSea) c->wall = waNone;
+  else if(c->wall == waSea) c->wall = waShallow;
+  else if(c->wall == waDeepWater) c->wall = waShallow;
+  else if(c->wall == waShallow) c->wall = waNone;
+  else if(c->wall == waLake) c->wall = waShallow;
   else if(isWateryOrBoat(c) || c->wall == waFrozenLake) c->wall = waNone;
   else if(isWateryOrBoat(c) || c->wall == waFrozenLake) c->wall = waNone;
   else if(cellHalfvine(c)) {
diff --git a/orbs.cpp b/orbs.cpp
index 54418dcd..e90e2290 100644
--- a/orbs.cpp
+++ b/orbs.cpp
@@ -432,7 +432,7 @@ EX void castLightningBolt(cellwalker lig) {
       brk = true;
       }
                              
-    if(c->wall == waBoat && c != cwt.at)    c->wall = waSea, spin = true;
+    if(c->wall == waBoat && c != cwt.at)    become_water(c), spin = true;
     if(c->wall == waStrandedBoat && c !=cwt.at)    c->wall = waNone, spin = true;
 
     if((c->wall == waNone || c->wall == waSea) && c->land == laLivefjord)
@@ -987,7 +987,7 @@ void blowoff(const movei& mi) {
     bool was_stranded = cf->wall == waStrandedBoat;
     bool willbe_stranded = ct->wall == waNone;
     if(was_stranded) cf->wall = waBoat;
-    if(willbe_stranded) ct->wall = waSea;
+    if(willbe_stranded) become_water(ct);
     moveBoat(mi);
     if(was_stranded) cf->wall = waNone;
     if(willbe_stranded) ct->wall = waStrandedBoat;
diff --git a/passable.cpp b/passable.cpp
index a1a13d98..56d0fb2c 100644
--- a/passable.cpp
+++ b/passable.cpp
@@ -41,15 +41,21 @@ EX bool boatGoesThrough(cell *c) {
     c->wall == waArrowTrap;
   }
 
+EX void become_water(cell *c) {
+  if(isIcyLand(c))
+    c->wall = waLake;
+  else if(isCoastal(c) || isSealand(c))
+    c->wall = waSea;
+  else
+    c->wall = waDeepWater;
+  }
+
 EX void placeWater(cell *c, cell *c2) {
   destroyTrapsOn(c);
   if(isWatery(c)) ;
   else if(c2 && isAlchAny(c2))
     c->wall = c2->wall;
-  else if(isIcyLand(c))
-    c->wall = waLake;
-  else
-    c->wall = waSea;
+  else become_water(c);
   // destroy the ancient treasure!
   if(c->item == itBarrow) c->item = itNone;
   }
diff --git a/pcmove.cpp b/pcmove.cpp
index c9cb143c..33105a20 100644
--- a/pcmove.cpp
+++ b/pcmove.cpp
@@ -138,7 +138,7 @@ EX bool checkNeedMove(bool checkonly, bool attacking) {
     if(in_gravity_zone(cwt.at) && passable(cwt.at, NULL, P_ISPLAYER)) return false;
     addMessage(XLAT("Nothing to stand on here!"));
     }
-  else if(cwt.at->wall == waSea || cwt.at->wall == waCamelotMoat) {
+  else if(among(cwt.at->wall, waSea, waCamelotMoat, waLake, waDeepWater)) {
     if(markOrb(itOrbFish)) return false;
     if(markOrb2(itOrbAether)) return false;
     if(in_gravity_zone(cwt.at) && passable(cwt.at, NULL, P_ISPLAYER)) return false;