SHELL.diff

diff --git a/include/sm64.h b/include/sm64.h
index 7b8bb683..fe631bc6 100644
--- a/include/sm64.h
+++ b/include/sm64.h
@@ -123,7 +123,8 @@ enum GroundStep {
     GROUND_STEP_NONE,
     GROUND_STEP_HIT_WALL,
     GROUND_STEP_HIT_WALL_STOP_QSTEPS = GROUND_STEP_HIT_WALL,
-    GROUND_STEP_HIT_WALL_CONTINUE_QSTEPS
+    GROUND_STEP_HIT_WALL_CONTINUE_QSTEPS,
+    GROUND_STEP_ENTERED_WATER
 };
 
 enum AirStepCheck {
@@ -140,7 +141,8 @@ enum AirStep {
     AIR_STEP_GRABBED_CEILING,
     AIR_STEP_UNK,
     AIR_STEP_HIT_LAVA_WALL,
-    AIR_STEP_HIT_CEILING
+    AIR_STEP_HIT_CEILING,
+    AIR_STEP_SHELL_ENTERED_WATER
 };
 
 enum WaterStep {
diff --git a/src/game/behaviors/koopa_shell.inc.c b/src/game/behaviors/koopa_shell.inc.c
index becfbe34..9b2b2903 100644
--- a/src/game/behaviors/koopa_shell.inc.c
+++ b/src/game/behaviors/koopa_shell.inc.c
@@ -60,34 +60,33 @@ void koopa_shell_spawn_sparkles(f32 a) {
 }
 
 void bhv_koopa_shell_loop(void) {
-    struct Surface *floor;
+    struct Surface *sp34;
 
     obj_set_hitbox(o, &sKoopaShellHitbox);
     cur_obj_scale(1.0f);
 
     switch (o->oAction) {
-        case KOOPA_SHELL_ACT_MARIO_NOT_RIDING:
+        case 0:
             cur_obj_update_floor_and_walls();
             cur_obj_if_hit_wall_bounce_away();
 
             if (o->oInteractStatus & INT_STATUS_INTERACTED) {
-                o->oAction = KOOPA_SHELL_ACT_MARIO_RIDING;
+                o->oAction++;
             }
 
             o->oFaceAngleYaw += 0x1000;
             cur_obj_move_standard(-20);
             koopa_shell_spawn_sparkles(10.0f);
-            shell_despawn();
             break;
 
-        case KOOPA_SHELL_ACT_MARIO_RIDING:
+        case 1:
             obj_copy_pos(o, gMarioObject);
-            floor = cur_obj_update_floor_height_and_get_floor();
+            sp34 = cur_obj_update_floor_height_and_get_floor();
 
             if (absf(find_water_level(o->oPosX, o->oPosZ) - o->oPosY) < 10.0f) {
                 koopa_shell_spawn_water_drop();
             } else if (absf(o->oPosY - o->oFloorHeight) < 5.0f) {
-                if (floor != NULL && floor->type == SURFACE_BURNING) {
+                if (sp34 != NULL && sp34->type == 1) {
                     bhv_koopa_shell_flame_spawn();
                 } else {
                     koopa_shell_spawn_sparkles(10.0f);
@@ -95,16 +94,17 @@ void bhv_koopa_shell_loop(void) {
             } else {
                 koopa_shell_spawn_sparkles(10.0f);
             }
-
+            o->oFaceAngleRoll = 0;
+            o->oFaceAnglePitch = 0;
             o->oFaceAngleYaw = gMarioObject->oMoveAngleYaw;
 
             if (o->oInteractStatus & INT_STATUS_STOP_RIDING) {
                 obj_mark_for_deletion(o);
                 spawn_mist_particles();
-                o->oAction = KOOPA_SHELL_ACT_MARIO_NOT_RIDING;
+                o->oAction = 0;
             }
             break;
     }
 
-    o->oInteractStatus = INT_STATUS_NONE;
+    o->oInteractStatus = 0;
 }
diff --git a/src/game/mario.c b/src/game/mario.c
index 90f4da1d..c699185c 100644
--- a/src/game/mario.c
+++ b/src/game/mario.c
@@ -1131,23 +1131,41 @@ s32 set_water_plunge_action(struct MarioState *m) {
     m->forwardVel = m->forwardVel / 4.0f;
     m->vel[1] = m->vel[1] / 2.0f;
 
-#ifdef WATER_PLUNGE_UPWARP
+    #ifdef WATER_PLUNGE_UPWARP
     m->pos[1] = m->waterLevel - 100;
-#endif
+    #endif
 
     m->faceAngle[2] = 0;
 
-    vec3_zero(m->angleVel);
+    vec3s_set(m->angleVel, 0, 0, 0);
 
     if (!(m->action & ACT_FLAG_DIVING)) {
         m->faceAngle[0] = 0;
     }
 
-    if (m->area->camera->mode != WATER_SURFACE_CAMERA_MODE) {
-        set_camera_mode(m->area->camera, WATER_SURFACE_CAMERA_MODE, 1);
+    if (m->area->camera->mode != CAMERA_MODE_WATER_SURFACE) {
+        set_camera_mode(m->area->camera, CAMERA_MODE_WATER_SURFACE, 1);
     }
 
+    if (m->actionState == 4 || (m->actionState == 6 && m->heldObj)) {
+        //do the water plunge stuff without entering the water plunge action
+        play_sound(SOUND_ACTION_WATER_PLUNGE, m->marioObj->header.gfx.cameraToObject);
+        if (m->peakHeight - m->pos[1] > 1150.0f) {
+            play_sound(SOUND_MARIO_HAHA_WATER, m->marioObj->header.gfx.cameraToObject);
+        }
+    m->pos[1] -= 200.0f;
+    m->vel[1] = -30.0f;
+        m->particleFlags |= PARTICLE_WATER_SPLASH;
+#if ENABLE_RUMBLE
+        if (m->prevAction & ACT_FLAG_AIR) {
+            queue_rumble_data(5, 80);
+        }
+#endif
+//cut straight to water shell swimming to avoid being slowed down and action transition hell
+            return set_mario_action(m, ACT_WATER_SHELL_SWIMMING, (u32)(s32)m->forwardVel);
+        }
     return set_mario_action(m, ACT_WATER_PLUNGE, 0);
+        
 }
 
 /**
@@ -1164,7 +1182,9 @@ void squish_mario_model(struct MarioState *m) {
     if (m->squishTimer != 0xFF) {
         // If no longer squished, scale back to default.
         if (m->squishTimer == 0) {
+            if (m->action != ACT_RIDING_SHELL_FALL && m->action != ACT_RIDING_SHELL_JUMP) {
             vec3f_set(m->marioObj->header.gfx.scale, 1.0f, 1.0f, 1.0f);
+            }
         }
         // If timer is less than 16, rubber-band Mario's size scale up and down.
         else if (m->squishTimer <= 16) {
diff --git a/src/game/mario_actions_airborne.c b/src/game/mario_actions_airborne.c
index 13c2b626..249553a0 100644
--- a/src/game/mario_actions_airborne.c
+++ b/src/game/mario_actions_airborne.c
@@ -14,6 +14,7 @@
 #include "mario_step.h"
 #include "save_file.h"
 #include "rumble_init.h"
+#include "behavior_data.h"
 
 #include "config.h"
 
@@ -663,11 +664,103 @@ s32 act_riding_shell_air(struct MarioState *m) {
     play_mario_sound(m, SOUND_ACTION_TERRAIN_JUMP, 0);
     set_mario_animation(m, MARIO_ANIM_JUMP_RIDING_SHELL);
 
+    // transfer the timer from the previous action
+    if (m->actionArg > 0) {
+        m->actionTimer = m->actionArg;
+        m->actionArg = 0;
+    } else {
+        // double jump
+        // putting this in an else statement ensures that the same A press is not used for the double
+        // jump
+        if (m->input & INPUT_A_PRESSED && m->actionState != 2 && m->actionState != 3) {
+            m->actionState = 2;
+            m->vel[1] = 60.0f;
+            m->particleFlags |= PARTICLE_MIST_CIRCLE;
+            play_sound(SOUND_GENERAL_WING_FLAP, m->marioObj->header.gfx.cameraToObject);
+        }
+    }
+
+    //this is in place for the transition from water shell to air shell
+    if (!m->riddenObj) {
+        m->faceAngle[0] = 0;
+        m->faceAngle[2] = 0;
+        m->interactObj = spawn_object(m->marioObj, MODEL_KOOPA_SHELL, bhvKoopaShell);
+            m->usedObj = m->interactObj;
+            m->riddenObj = m->interactObj;
+
+            attack_object(m->interactObj, 0x40);
+    }
+
+    m->actionTimer++;
+
+
+    //ground pound
+    if (m->input & INPUT_Z_PRESSED && m->actionState != 3) {
+        m->actionState = 3;
+        m->forwardVel *= 0.7f;
+        // the timer is set to 40 so that the dash will be ready when you get back to the ground
+        m->actionTimer = 40;
+
+        play_sound(SOUND_ACTION_SPIN, m->marioObj->header.gfx.cameraToObject);
+    }
+
+    if (m->actionState == 3) {
+        // stall in the air for a bit
+        if (m->actionTimer < 45) {
+            m->marioObj->header.gfx.angle[1] += 0x3333;
+        }
+        if (m->actionTimer < 50) {
+            m->vel[1] = 12.0f;
+        }
+        // shoot downward
+        if (m->actionTimer == 50) {
+            m->vel[1] = -90.0f;
+        }
+    }
+
+    // manual deceleration in air during a dash
+    if (m->forwardVel < 128.0f && m->forwardVel > 64.0f) {
+        m->forwardVel -= (f32) m->actionTimer / 15.0f;
+    }
+    if (m->forwardVel > 128.0f) {
+        m->forwardVel = 128.0f;
+    }
+
+    // accelerate downwards during pound
+    if (m->actionState == 3) {
+        m->vel[1] -= 10.0f;
+        if (m->vel[1] < -90.0f) {
+            m->marioObj->header.gfx.scale[1] = 1.0f + (-1.0f * m->vel[1] / 180.0f);
+        }
+    }
+
     update_air_without_turn(m);
 
     switch (perform_air_step(m, 0)) {
         case AIR_STEP_LANDED:
-            set_mario_action(m, ACT_RIDING_SHELL_GROUND, 1);
+            if (m->actionState == 3) {
+
+                // ground pounds go straight into water
+                if (m->floor == &gWaterSurfacePseudoFloor) {
+                    if (m->riddenObj != NULL) {
+                        m->riddenObj->oInteractStatus = INT_STATUS_STOP_RIDING;
+                        m->riddenObj = NULL;
+                    }
+                    play_sound(SOUND_ACTION_WATER_PLUNGE, m->marioObj->header.gfx.cameraToObject);
+                    m->particleFlags |= PARTICLE_WATER_SPLASH;
+                    m->pos[1] -= 50;
+                     m->usedObj = spawn_object(m->marioObj, MODEL_KOOPA_SHELL, bhvKoopaShellUnderwater);
+                     mario_grab_used_object(m);
+                    m->marioBodyState->grabPos = GRAB_POS_LIGHT_OBJ;
+                    set_mario_action(m, ACT_WATER_SHELL_SWIMMING, (u32)(s32)m->forwardVel);
+                } else {
+                    m->particleFlags |= PARTICLE_MIST_CIRCLE;
+                    play_sound(SOUND_OBJ_POUNDING1, m->marioObj->header.gfx.cameraToObject);
+                    set_mario_action(m, ACT_RIDING_SHELL_GROUND, m->actionTimer);
+                }
+            } else {
+                set_mario_action(m, ACT_RIDING_SHELL_GROUND, m->actionTimer);
+            }
             break;
 
         case AIR_STEP_HIT_WALL:
@@ -677,6 +770,18 @@ s32 act_riding_shell_air(struct MarioState *m) {
         case AIR_STEP_HIT_LAVA_WALL:
             lava_boost_on_wall(m);
             break;
+
+        case AIR_STEP_SHELL_ENTERED_WATER:
+            if (m->riddenObj != NULL) {
+                m->riddenObj->oInteractStatus = INT_STATUS_STOP_RIDING;
+                m->riddenObj = NULL;
+            }
+            play_sound(SOUND_ACTION_WATER_PLUNGE, m->marioObj->header.gfx.cameraToObject);
+            m->particleFlags |= PARTICLE_WATER_SPLASH;
+            m->pos[1] -= 50;
+            //changes action but doesnt spawn a shell. the shell will spawn in the action itself.
+            set_mario_action(m, ACT_WATER_SHELL_SWIMMING, (u32)(s32)m->forwardVel);
+            break;
     }
 
     m->marioObj->header.gfx.pos[1] += 42.0f;
@@ -862,21 +967,69 @@ s32 act_water_jump(struct MarioState *m) {
 }
 
 s32 act_hold_water_jump(struct MarioState *m) {
-    if (m->marioObj->oInteractStatus & INT_STATUS_MARIO_DROP_OBJECT) {
-        return drop_and_set_mario_action(m, ACT_FREEFALL, 0);
+    // transfer actionArg to actionState if holding a shell
+    if (m->actionArg == 4) {
+        m->vel[1] = m->forwardVel * 1.9f;
+        m->forwardVel *= 1.6f;
+        m->actionArg = 0;
+        m->actionState = 4;
+
+        // the water cam is awful for this, just use the normal one instead
+        set_camera_mode(m->area->camera, m->area->camera->defMode, 1);
     }
+    m->actionTimer += 1;
 
     if (m->forwardVel < 15.0f) {
         mario_set_forward_vel(m, 15.0f);
     }
 
+    //if Z is pressed midair, mario will do a flip and then go back to riding his shell
+    if (m->input & INPUT_Z_PRESSED && m->actionState != 6) {
+        m->actionState = 6;
+        m->actionTimer = 0;
+    }
+
+    // apparently air step doesnt use fvel???
+    m->vel[0] = m->forwardVel * coss(m->faceAngle[0]) * sins(m->faceAngle[1]);
+    m->vel[2] = m->forwardVel * coss(m->faceAngle[0]) * coss(m->faceAngle[1]);
+
     play_mario_sound(m, SOUND_ACTION_WATER_JUMP, 0);
-    set_mario_animation(m, MARIO_ANIM_JUMP_WITH_LIGHT_OBJ);
+
+    // if holding the shell, do a midair spin instead of a normal jump
+    if (m->actionState == 4) {
+        set_mario_animation(m, MARIO_ANIM_SLIDE_DIVE);
+        m->marioObj->header.gfx.angle[2] += 0x2000;
+        m->marioObj->header.gfx.angle[0] = -0x80 * m->vel[1];
+    } else {
+        set_mario_animation(m, MARIO_ANIM_JUMP_WITH_LIGHT_OBJ);
+    }
+
+    //frontflip a few times and then go into the air shell action
+    if (m->actionState == 6) {
+        if (m->actionTimer < 10) {
+            m->marioObj->header.gfx.angle[0] += 0x3333;
+            m->marioObj->header.gfx.angle[2] = 0;
+        }
+        else {
+            m->heldObj = NULL;
+                set_camera_mode(m->area->camera, m->area->camera->defMode, 1);
+            return set_mario_action(m, ACT_RIDING_SHELL_JUMP, m->actionTimer);
+        }
+    }
 
     switch (perform_air_step(m, 0)) {
         case AIR_STEP_LANDED:
-            set_mario_action(m, ACT_HOLD_JUMP_LAND, 0);
-            set_camera_mode(m->area->camera, m->area->camera->defMode, 1);
+            // only under extreme circumstances would you be able to hold something other than a shell
+            // underwater. still, better safe than sorry
+            if (m->actionState == 4 || m->actionState == 6) {
+                set_mario_action(m, ACT_RIDING_SHELL_GROUND, m->actionState);
+                m->heldObj = NULL;
+
+                set_camera_mode(m->area->camera, m->area->camera->defMode, 1);
+            } else {
+                set_mario_action(m, ACT_HOLD_JUMP_LAND, m->actionState);
+                set_camera_mode(m->area->camera, m->area->camera->defMode, 1);
+            }
             break;
 
         case AIR_STEP_HIT_WALL:
diff --git a/src/game/mario_actions_moving.c b/src/game/mario_actions_moving.c
index 23dc7a87..6ba5a948 100644
--- a/src/game/mario_actions_moving.c
+++ b/src/game/mario_actions_moving.c
@@ -336,9 +336,9 @@ void update_shell_speed(struct MarioState *m) {
     f32 targetSpeed;
 
     if (m->floorHeight < m->waterLevel) {
-        set_mario_floor(m, &gWaterSurfacePseudoFloor, m->waterLevel);
+        m->floorHeight = m->waterLevel;
+        m->floor = &gWaterSurfacePseudoFloor;
         m->floor->originOffset = -m->waterLevel;
-        // m->floor->originOffset = m->waterLevel; //! (Original code) Negative origin offset
     }
 
     if (m->floor != NULL && m->floor->type == SURFACE_SLOW) {
@@ -351,7 +351,8 @@ void update_shell_speed(struct MarioState *m) {
     if (targetSpeed > maxTargetSpeed) {
         targetSpeed = maxTargetSpeed;
     }
-    if (targetSpeed < 24.0f) {
+    //make sure a minimum speed isnt being set when braking
+    if (targetSpeed < 24.0f && !(m->input & INPUT_Z_DOWN)) {
         targetSpeed = 24.0f;
     }
 
@@ -363,9 +364,27 @@ void update_shell_speed(struct MarioState *m) {
         m->forwardVel -= 1.0f;
     }
 
+    if (m->actionState == 1) {
+        m->forwardVel -= (f32) m->actionTimer / 10.0f;
+        //increase max speed for the shell dash
+        if (m->forwardVel > 128.0f) { 
+           m->forwardVel = 128.0f;
+       }
+       if (m->forwardVel < 64.0f) { 
+           m->actionState = 0;
+        }
+    }
     //! No backward speed cap (shell hyperspeed)
-    if (m->forwardVel > 64.0f) {
-        m->forwardVel = 64.0f;
+    else {
+        //use vanilla speed
+        if (m->forwardVel > 64.0f) {
+            m->forwardVel = 64.0f;
+        }
+    }
+
+    //braking
+    if (m->input & INPUT_Z_DOWN) {
+        m->forwardVel *= 0.9;
     }
 
     m->faceAngle[1] =
@@ -1196,11 +1215,46 @@ s32 act_hold_decelerating(struct MarioState *m) {
 s32 act_riding_shell_ground(struct MarioState *m) {
     s16 startYaw = m->faceAngle[1];
 
+    //transfer the timer from the previous action
+    if (m->actionArg > 0) {
+        m->actionTimer = m->actionArg;
+        m->actionArg = 0;
+    }
+
+    //this is in place for the transition from water shell to ground shell
+    if (!m->riddenObj) {
+        m->faceAngle[0] = 0;
+        m->faceAngle[2] = 0;
+        m->interactObj = spawn_object(m->marioObj, MODEL_KOOPA_SHELL, bhvKoopaShell);
+            m->usedObj = m->interactObj;
+            m->riddenObj = m->interactObj;
+
+            attack_object(m->interactObj, 0x40);
+    }
+
+    m->actionTimer++;
+
     if (m->input & INPUT_A_PRESSED) {
-        return set_mario_action(m, ACT_RIDING_SHELL_JUMP, 0);
+        return set_mario_action(m, ACT_RIDING_SHELL_JUMP, m->actionTimer);
+    }
+
+    //shell dash
+    if (m->input & INPUT_B_PRESSED && m->actionState != 1 && m->actionTimer >= 60) {
+        m->particleFlags |= PARTICLE_VERTICAL_STAR;
+        play_sound(SOUND_OBJ_WATER_BOMB_CANNON, m->marioObj->header.gfx.cameraToObject);
+        set_camera_shake_from_hit(SHAKE_HIT_FROM_BELOW);
+        //make mario go at least max shell speed
+        m->forwardVel *= 2.0f;
+        if (m->forwardVel < 64.0f) {
+            m->forwardVel = 64.0f;
+        }
+        //set state to shell dash, reset timer
+        m->actionState = 1;
+        m->actionTimer = 0;
     }
 
-    if (m->input & INPUT_Z_PRESSED) {
+    //get off the shell
+    if (m->input & INPUT_Z_DOWN && m->input & INPUT_B_PRESSED) {
         mario_stop_riding_object(m);
         if (m->forwardVel < 24.0f) {
             mario_set_forward_vel(m, 24.0f);
@@ -1217,12 +1271,32 @@ s32 act_riding_shell_ground(struct MarioState *m) {
             break;
 
         case GROUND_STEP_HIT_WALL:
+            //no more shell breaking! instead, mario will just lose all speed
+            /*
             mario_stop_riding_object(m);
             play_sound(m->flags & MARIO_METAL_CAP ? SOUND_ACTION_METAL_BONK : SOUND_ACTION_BONK,
                        m->marioObj->header.gfx.cameraToObject);
             m->particleFlags |= PARTICLE_VERTICAL_STAR;
             set_mario_action(m, ACT_BACKWARD_GROUND_KB, 0);
+            */
+            m->forwardVel = 0;
             break;
+
+        case GROUND_STEP_ENTERED_WATER:
+            return FALSE;
+    }
+
+    //if mario presses Z over a water surface, switch to the water shell
+    if (m->floor == &gWaterSurfacePseudoFloor && m->input & INPUT_Z_PRESSED) {
+        if (m->riddenObj != NULL) {
+            m->riddenObj->oInteractStatus = INT_STATUS_STOP_RIDING;
+            m->riddenObj = NULL;
+        }
+        m->usedObj = spawn_object(m->marioObj, MODEL_KOOPA_SHELL, bhvKoopaShellUnderwater);
+        mario_grab_used_object(m);
+        m->marioBodyState->grabPos = GRAB_POS_LIGHT_OBJ;
+        m->pos[1] -= 50;
+        set_mario_action(m, ACT_WATER_SHELL_SWIMMING, (u32)(s32)m->forwardVel);
     }
 
     tilt_body_ground_shell(m, startYaw);
@@ -1235,7 +1309,7 @@ s32 act_riding_shell_ground(struct MarioState *m) {
 
     adjust_sound_for_speed(m);
 #if ENABLE_RUMBLE
-    reset_rumble_timers_slip();
+    reset_rumble_timers();
 #endif
     return FALSE;
 }
diff --git a/src/game/mario_actions_submerged.c b/src/game/mario_actions_submerged.c
index 2fb2238f..7a97daa2 100644
--- a/src/game/mario_actions_submerged.c
+++ b/src/game/mario_actions_submerged.c
@@ -228,6 +228,11 @@ static void update_swimming_speed(struct MarioState *m, f32 decelThreshold) {
     f32 buoyancy = get_buoyancy(m);
     f32 maxSpeed = 28.0f;
 
+    //if mario is using a shell he can go much faster
+    if (m->heldObj) {
+        maxSpeed = 130.0f;
+    }
+
     if (m->action & ACT_FLAG_STATIONARY) {
         m->forwardVel -= 2.0f;
     }
@@ -487,17 +492,30 @@ static void play_swimming_noise(struct MarioState *m) {
 
 static s32 check_water_jump(struct MarioState *m) {
     s32 probe = (s32)(m->pos[1] + 1.5f);
-
-    if (m->input & INPUT_A_PRESSED) {
+    
+    if (m->input & INPUT_A_PRESSED || m->action == ACT_WATER_SHELL_SWIMMING) {
         if (probe >= m->waterLevel - 80 && m->faceAngle[0] >= 0 && m->controller->stickY < -60.0f) {
-            vec3_zero(m->angleVel);
+            vec3s_set(m->angleVel, 0, 0, 0);
 
             m->vel[1] = 62.0f;
 
             if (m->heldObj == NULL) {
                 return set_mario_action(m, ACT_WATER_JUMP, 0);
             } else {
-                return set_mario_action(m, ACT_HOLD_WATER_JUMP, 0);
+                //mario is doing a water dash and going WAY too fast. cut his speed a bit
+                if (m->actionState == 5) {
+                    m->forwardVel *= 0.6f;
+                    if (m->forwardVel < 40.0f) {
+                        m->forwardVel = 40.0f;
+                    }
+                }
+                if (m->forwardVel > 50.0f) {
+                    m->forwardVel = 50.0f;
+                }
+                m->actionState = 4;
+                play_sound(SOUND_ACTION_WATER_PLUNGE, m->marioObj->header.gfx.cameraToObject);
+                m->particleFlags |= PARTICLE_WATER_SPLASH;
+                return set_mario_action(m, ACT_HOLD_WATER_JUMP, 4);
             }
         }
     }
@@ -742,26 +760,73 @@ static s32 act_hold_flutter_kick(struct MarioState *m) {
 }
 
 static s32 act_water_shell_swimming(struct MarioState *m) {
+
+    //transfer forward velocity when entering water
+    if (((s32)m->actionArg > 0)) {
+        m->forwardVel = ((s32)m->actionArg);
+        m->actionArg = 0;
+    }
+
+    if (!m->heldObj) {
+        m->usedObj = spawn_object(m->marioObj, MODEL_KOOPA_SHELL, bhvKoopaShellUnderwater);
+        mario_grab_used_object(m);
+        m->marioBodyState->grabPos = GRAB_POS_LIGHT_OBJ;
+    }
+
+    m->actionTimer += 1;
+
+
     if (m->marioObj->oInteractStatus & INT_STATUS_MARIO_DROP_OBJECT) {
         return drop_and_set_mario_action(m, ACT_WATER_IDLE, 0);
     }
 
-    if (m->input & INPUT_B_PRESSED) {
-        return set_mario_action(m, ACT_WATER_THROW, 0);
+    //underwater shell dash
+    if (m->input & INPUT_B_PRESSED && m->actionState != 5) {
+        //return set_mario_action(m, ACT_WATER_THROW, 0);
+        m->particleFlags |= PARTICLE_VERTICAL_STAR;
+        play_sound(SOUND_OBJ_WATER_BOMB_CANNON, m->marioObj->header.gfx.cameraToObject);
+        m->actionState = 5;
+        m->forwardVel *= 2;
     }
 
+    //water shell timer is really stupid tbh
+/*
     if (m->actionTimer++ == 240) {
         m->heldObj->oInteractStatus = INT_STATUS_STOP_RIDING;
         m->heldObj = NULL;
         stop_shell_music();
         set_mario_action(m, ACT_FLUTTER_KICK, 0);
     }
+    */
 
-    m->forwardVel = approach_f32(m->forwardVel, 30.0f, 2.0f, 1.0f);
+   
+
+   if (m->forwardVel <= 40.0f) {
+       if (m->actionState == 5) {
+           m->actionState = 0;
+       }
+    //braking
+   if (m->input & INPUT_Z_DOWN) {
+        m->forwardVel = approach_f32(m->forwardVel, 0.0f, 2.0f, 0.2f);
+   }
+   //normal speed
+   else {
+       m->forwardVel = approach_f32(m->forwardVel, 40.0f, 2.0f, 1.0f);
+   }
+    }
+    //if dashing, approach the normal speed faster
+    else {
+        m->forwardVel = approach_f32(m->forwardVel, 40.0f, 2.0f, 1.0f);
+        //m->marioObj->header.gfx.angle[2] += 0x2000;
+    }
 
     play_swimming_noise(m);
     set_mario_animation(m, MARIO_ANIM_FLUTTERKICK_WITH_OBJ);
-    common_swimming_step(m, 300);
+    //check to see if mario wants to do the spin jump out of the water
+    if (m->actionTimer > 5) {
+    check_water_jump(m);  
+    }
+    common_swimming_step(m, 0x012C);
 
     return FALSE;
 }
@@ -1497,19 +1562,38 @@ static s32 check_common_submerged_cancels(struct MarioState *m) {
         if (waterHeight > m->floorHeight) {
             if (m->pos[1] - waterHeight < 50) {
                 m->pos[1] = waterHeight; // lock mario to top if the falloff isn't big enough
-            } else {
+            } 
+            else if (m->action == ACT_WATER_SHELL_SWIMMING && m->heldObj != NULL) {
+                if (m->forwardVel > 50.0f) {
+                    m->forwardVel = 50.0f;
+                }
+                m->actionState = 4;
+                play_sound(SOUND_ACTION_WATER_PLUNGE, m->marioObj->header.gfx.cameraToObject);
+                m->particleFlags |= PARTICLE_WATER_SPLASH;
+                return set_mario_action(m, ACT_HOLD_WATER_JUMP, 40);
+            }
+            else {
                 // m->pos[1] = m->waterLevel - 80; // Vanilla bug: Downwarp swimming out of waterfalls
                 return transition_submerged_to_airborne(m);
             }
         } else {
-            //! If you press B to throw the shell, there is a ~5 frame window
-            // where your held object is the shell, but you are not in the
-            // water shell swimming action. This allows you to hold the water
-            // shell on land (used for cloning in DDD).
             if (m->action == ACT_WATER_SHELL_SWIMMING && m->heldObj != NULL) {
-                m->heldObj->oInteractStatus = INT_STATUS_STOP_RIDING;
+                if (m->pos[1] - m->floorHeight > 100) {
+                //exit the water in the shell spin state
+                if (m->forwardVel > 50.0f) {
+                    m->forwardVel = 50.0f;
+                }
+                m->actionState = 4;
+                play_sound(SOUND_ACTION_WATER_PLUNGE, m->marioObj->header.gfx.cameraToObject);
+                m->particleFlags |= PARTICLE_WATER_SPLASH;
+                return set_mario_action(m, ACT_HOLD_WATER_JUMP, 40);
+            }
+            else {
+                //exit the water in a generic air shell state
                 m->heldObj = NULL;
-                stop_shell_music();
+                set_camera_mode(m->area->camera, m->area->camera->defMode, 1);
+                return set_mario_action(m, ACT_RIDING_SHELL_JUMP, m->actionTimer);
+            }
             }
 
             return transition_submerged_to_walking(m);
diff --git a/src/game/mario_step.c b/src/game/mario_step.c
index 2b1ceb08..f0c8bc55 100644
--- a/src/game/mario_step.c
+++ b/src/game/mario_step.c
@@ -9,6 +9,7 @@
 #include "game_init.h"
 #include "interaction.h"
 #include "mario_step.h"
+#include "behavior_data.h"
 
 #include "config.h"
 
@@ -291,10 +292,27 @@ static s32 perform_ground_quarter_step(struct MarioState *m, Vec3f nextPos) {
         return GROUND_STEP_HIT_WALL_STOP_QSTEPS;
     }
 
-    if ((m->action & ACT_FLAG_RIDING_SHELL) && floorHeight < waterLevel) {
-        floorHeight = waterLevel;
-        floor = &gWaterSurfacePseudoFloor;
-        floor->originOffset = -floorHeight;
+    if (m->action & ACT_FLAG_RIDING_SHELL) {
+        if (m->pos[1] < waterLevel - 100) {
+            if (m->riddenObj != NULL) {
+                m->riddenObj->oInteractStatus = INT_STATUS_STOP_RIDING;
+                m->riddenObj = NULL;
+            }
+
+            m->usedObj = spawn_object(m->marioObj, MODEL_KOOPA_SHELL, bhvKoopaShellUnderwater);
+            mario_grab_used_object(m);
+            m->marioBodyState->grabPos = GRAB_POS_LIGHT_OBJ;
+            set_mario_action(m, ACT_WATER_SHELL_SWIMMING, (u32)(s32)m->forwardVel);
+            m->pos[0] = nextPos[0];
+            m->pos[1] = MIN(m->pos[1], waterLevel - 120);
+            m->pos[2] = nextPos[2];
+            return GROUND_STEP_ENTERED_WATER;
+        }
+        else if (floorHeight < waterLevel) {
+            floorHeight = waterLevel;
+            floor = &gWaterSurfacePseudoFloor;
+            floor->originOffset = -floorHeight;
+        }
     }
 
     if (nextPos[1] > floorHeight + 100.0f) {
@@ -356,7 +374,11 @@ s32 perform_ground_step(struct MarioState *m) {
         intendedPos[1] = m->pos[1];
 
         stepResult = perform_ground_quarter_step(m, intendedPos);
-        if (stepResult == GROUND_STEP_LEFT_GROUND || stepResult == GROUND_STEP_HIT_WALL_STOP_QSTEPS) {
+        if (
+            stepResult == GROUND_STEP_LEFT_GROUND
+            || stepResult == GROUND_STEP_HIT_WALL_STOP_QSTEPS
+            || stepResult == GROUND_STEP_ENTERED_WATER
+        ) {
             break;
         }
     }
@@ -482,10 +504,27 @@ s32 perform_air_quarter_step(struct MarioState *m, Vec3f intendedPos, u32 stepAr
         return AIR_STEP_HIT_WALL;
     }
 
-    if ((m->action & ACT_FLAG_RIDING_SHELL) && floorHeight < waterLevel) {
-        floorHeight = waterLevel;
-        floor = &gWaterSurfacePseudoFloor;
-        floor->originOffset = -floorHeight;
+    if (m->action & ACT_FLAG_RIDING_SHELL) {
+        if (m->pos[1] < waterLevel - 100) {
+            if (m->riddenObj != NULL) {
+                m->riddenObj->oInteractStatus = INT_STATUS_STOP_RIDING;
+                m->riddenObj = NULL;
+            }
+
+            m->usedObj = spawn_object(m->marioObj, MODEL_KOOPA_SHELL, bhvKoopaShellUnderwater);
+            mario_grab_used_object(m);
+            m->marioBodyState->grabPos = GRAB_POS_LIGHT_OBJ;
+            set_mario_action(m, ACT_WATER_SHELL_SWIMMING, (u32)(s32)m->forwardVel);
+            m->pos[0] = nextPos[0];
+            m->pos[1] = MIN(m->pos[1], waterLevel - 120);
+            m->pos[2] = nextPos[2];
+            return AIR_STEP_SHELL_ENTERED_WATER;
+        }
+        else if (floorHeight < waterLevel) {
+            floorHeight = waterLevel;
+            floor = &gWaterSurfacePseudoFloor;
+            floor->originOffset = -floorHeight;
+        }
     }
 
     //! This check uses f32, but findFloor uses short (overflow jumps)
@@ -694,9 +733,13 @@ s32 perform_air_step(struct MarioState *m, u32 stepArg) {
             stepResult = quarterStepResult;
         }
 
-        if (quarterStepResult == AIR_STEP_LANDED || quarterStepResult == AIR_STEP_GRABBED_LEDGE
+        if (
+            quarterStepResult == AIR_STEP_LANDED
+            || quarterStepResult == AIR_STEP_GRABBED_LEDGE
             || quarterStepResult == AIR_STEP_GRABBED_CEILING
-            || quarterStepResult == AIR_STEP_HIT_LAVA_WALL) {
+            || quarterStepResult == AIR_STEP_HIT_LAVA_WALL
+            || quarterStepResult == AIR_STEP_SHELL_ENTERED_WATER
+        ) {
             break;
         }
     }
@@ -713,7 +756,17 @@ s32 perform_air_step(struct MarioState *m, u32 stepArg) {
     apply_vertical_wind(m);
 
     vec3f_copy(m->marioObj->header.gfx.pos, m->pos);
-    vec3s_set(m->marioObj->header.gfx.angle, 0, m->faceAngle[1], 0);
+
+     //stop copying rotations if mario is doing a shell ground pound or a water shell spin.
+    if (
+        m->action != ACT_RIDING_SHELL_JUMP
+        && m->action != ACT_RIDING_SHELL_FALL
+        && m->action != ACT_HOLD_WATER_JUMP
+        && m->actionState != 3
+        && m->actionState != 4
+    ) {
+        vec3s_set(m->marioObj->header.gfx.angle, 0, m->faceAngle[1], 0);
+    }
 
     return stepResult;
 }