diff --git a/servers/world/src/common.rs b/servers/world/src/common.rs
index 2006314b..ccfa973c 100644
--- a/servers/world/src/common.rs
+++ b/servers/world/src/common.rs
@@ -287,8 +287,8 @@ pub enum ToServer {
         Option<f32>,
         Option<(WarpType, u8, u8, u8)>,
     ),
-    /// The player walks through a zone change line.
-    EnterZoneJump(ClientId, ObjectId, u32),
+    /// The player walks through a zone change line or passes through an underwater portal (e.g. in Ruby Sea).
+    EnterZoneJump(ClientId, ObjectId, u32, Option<(WarpType, u8, u8, u8)>),
     /// The connection disconnected.
     Disconnected(ClientId, ObjectId),
     /// A fatal error occured.
diff --git a/servers/world/src/main.rs b/servers/world/src/main.rs
index 975dd07d..62b0d589 100644
--- a/servers/world/src/main.rs
+++ b/servers/world/src/main.rs
@@ -1724,6 +1724,7 @@ async fn process_packet(
                                     connection.id,
                                     connection.player_data.character.actor_id,
                                     *exit_box,
+                                    None,
                                 ))
                                 .await;
                         }
@@ -2965,9 +2966,17 @@ async fn process_packet(
                             position,
                         } => {
                             match action {
-                                0xD1 => { // Underwater portal
-                                    // TODO: This uses param1 somehow. It doesn't appear to be a poprange or exit box. If it's an index into a sheet, I have no idea which.
-                                    // TODO: The ActorSetPos for underwater portals uses warp_type: WarpType::InstanceContent, param4 = 15, hide_character = 2, unk1 = 4.
+                                0xD1 => {
+                                    // Underwater portal
+                                    connection
+                                        .handle
+                                        .send(ToServer::EnterZoneJump(
+                                            connection.id,
+                                            connection.player_data.character.actor_id,
+                                            *param1,
+                                            Some((WarpType::InstanceContent, 15, 2, 4)),
+                                        ))
+                                        .await;
                                 }
                                 0x25F => {
                                     // Surfacing from diving
diff --git a/servers/world/src/server/mod.rs b/servers/world/src/server/mod.rs
index 9fe14fb6..1def25df 100644
--- a/servers/world/src/server/mod.rs
+++ b/servers/world/src/server/mod.rs
@@ -771,6 +771,9 @@ fn server_logic_tick(
             id,
             from_id,
             WarpType::InstanceContent,
+            0,
+            0,
+            0,
         );
     }
 }
diff --git a/servers/world/src/server/zone.rs b/servers/world/src/server/zone.rs
index 4ef3f6a4..524def12 100644
--- a/servers/world/src/server/zone.rs
+++ b/servers/world/src/server/zone.rs
@@ -832,6 +832,9 @@ pub fn change_zone_warp_to_pop_range(
     actor_id: ObjectId,
     from_id: ClientId,
     warp_type: WarpType,
+    param4: u8,
+    hide_character: u8,
+    unk1: u8,
 ) {
     let (target_instance, needs_init_zone) = begin_change_zone(
         data,
@@ -840,9 +843,9 @@ pub fn change_zone_warp_to_pop_range(
         destination_zone_id,
         actor_id,
         warp_type,
-        0,
-        0,
-        0,
+        param4,
+        hide_character,
+        unk1,
     )
     .unwrap();
 
@@ -1085,12 +1088,12 @@ pub fn handle_zone_messages(
 
             true
         }
-        ToServer::EnterZoneJump(from_id, actor_id, exitbox_id) => {
+        ToServer::EnterZoneJump(from_id, actor_id, exitbox_id, warp_type_info) => {
             let mut data = data.lock();
             let mut network = network.lock();
 
             // first, find the zone jump in the current zone
-            let destination_zone_id;
+            let mut destination_zone_id;
             let destination_instance_id;
             if let Some(current_instance) = data.find_actor_instance(*actor_id) {
                 let Some((_, new_exit_box)) = current_instance.zone.find_exit_box(*exitbox_id)
@@ -1099,12 +1102,28 @@ pub fn handle_zone_messages(
                     return true;
                 };
                 destination_zone_id = new_exit_box.territory_type;
+
+                // Seen when attempting to enter underwater portals in Ruby Sea
+                if new_exit_box.territory_type == 0
+                    && new_exit_box.zone_id == 0
+                    && new_exit_box.exit_type == physis::layer::ExitType::Unk
+                {
+                    destination_zone_id = current_instance.zone.id;
+                }
+
                 destination_instance_id = new_exit_box.destination_instance_id;
             } else {
                 tracing::warn!("Actor isn't in the instance it was expected in. This is a bug!");
                 return true;
             }
 
+            let (warp_type, param4, hide_character, unk1) =
+                if let Some((w_type, param, hide, unk)) = warp_type_info {
+                    (*w_type, *param, *hide, *unk)
+                } else {
+                    (WarpType::Normal, 0, 0, 0)
+                };
+
             let mut game_data = game_data.lock();
             change_zone_warp_to_pop_range(
                 &mut data,
@@ -1114,7 +1133,10 @@ pub fn handle_zone_messages(
                 destination_instance_id,
                 *actor_id,
                 *from_id,
-                WarpType::Normal,
+                warp_type,
+                param4,
+                hide_character,
+                unk1,
             );
 
             true
@@ -1138,6 +1160,9 @@ pub fn handle_zone_messages(
                 *actor_id,
                 *from_id,
                 WarpType::Normal,
+                0,
+                0,
+                0,
             );
 
             true
@@ -1161,6 +1186,9 @@ pub fn handle_zone_messages(
                 *actor_id,
                 *from_id,
                 WarpType::Normal,
+                0,
+                0,
+                0,
             );
 
             true
@@ -1179,6 +1207,9 @@ pub fn handle_zone_messages(
                 *from_actor_id,
                 *from_id,
                 WarpType::Normal,
+                0,
+                0,
+                0,
             );
 
             true
@@ -1254,6 +1285,9 @@ pub fn handle_zone_messages(
                 } else {
                     WarpType::None
                 },
+                0,
+                0,
+                0,
             );
 
             true