diff --git a/src/Aquarium.cpp b/src/Aquarium.cpp
index 1437efa..3c87ba4 100644
--- a/src/Aquarium.cpp
+++ b/src/Aquarium.cpp
@@ -91,7 +91,7 @@ void Aquarium::redraw() {
     auto &bubble = *it;
     bubble->draw();
     bubble->update();
-    if (bubble->getY() < 9)
+    if (bubble->isOutOfWater())
       it = bubbles.erase(it);
     else
       ++it;
@@ -137,7 +137,7 @@ void Aquarium::redraw() {
   applyBackBuffer();
 }
 
-void Aquarium::addBubble(float x, float y) {
+void Aquarium::addBubble(size_t x, size_t y) {
   bubbles.emplace_back(std::make_unique<Bubble>(x, y));
 }
 
diff --git a/src/Aquarium.h b/src/Aquarium.h
index 72b6a43..913d29f 100644
--- a/src/Aquarium.h
+++ b/src/Aquarium.h
@@ -80,7 +80,7 @@ public:
   [[nodiscard]] int getWidth() const { return width; }
   [[nodiscard]] int getHeight() const { return height; }
   void addFish();
-  void addBubble(float x, float y);
+  void addBubble(size_t x, size_t y);
   void addSeaweed();
   void addWaterline();
   void addCastle();
diff --git a/src/Bubble.cpp b/src/Bubble.cpp
index 3a6ca49..01f98a4 100644
--- a/src/Bubble.cpp
+++ b/src/Bubble.cpp
@@ -2,25 +2,17 @@
 #include "Aquarium.h"
 #include <ncurses.h>
 
-Bubble::Bubble(float x, float y) : Entity() {
-  this->x = x;
-  this->y = y;
+Bubble::Bubble(size_t x, size_t y) : x(x), y(y) {}
+
+void Bubble::update() {
+  --y;
+  ++lifetime;
 }
 
-void Bubble::update() { y -= 1; }
-
-void Bubble::draw() {
-  lifetime++;
-
-  // Determine the frame based on lifetime
-  int frameNumber = lifetime / 9;
-  if (frameNumber > 2)
-    frameNumber = 2;
-
-  char frame = bubbleChars[frameNumber];
-
-  std::string line(1, frame);
-  std::string colorLine(1, 'c');
-
-  Aquarium::getInstance().drawToBackBuffer(y, x, 0, line, colorLine);
+void Bubble::draw() const {
+  static const std::string colorString(1, BUBBLE_COLOR);
+  // Clamp frame index
+  int frameIndex = std::min(lifetime / FRAMES_PER_ANIMATION, MAX_FRAME_INDEX);
+  Aquarium::getInstance().drawToBackBuffer(y, x, 0, BUBBLE_FRAMES[frameIndex],
+                                           colorString);
 }
diff --git a/src/Bubble.h b/src/Bubble.h
index a9bfd59..761db1b 100644
--- a/src/Bubble.h
+++ b/src/Bubble.h
@@ -1,14 +1,21 @@
 #pragma once
-#include "Entity.h"
+#include <cstddef>
+#include <string>
 
-class Bubble : public Entity {
+class Bubble {
 private:
-  static constexpr char bubbleChars[3] = {'.', 'o', 'O'};
+  static constexpr const char *BUBBLE_FRAMES[3] = {".", "o", "O"};
+  static constexpr int FRAMES_PER_ANIMATION = 9;
+  static constexpr int MAX_FRAME_INDEX = 2;
+  static constexpr char BUBBLE_COLOR = 'c';
+  size_t x, y;
   int lifetime = 0;
 
 public:
-  Bubble(float x, float y);
+  Bubble(size_t x, size_t y);
+
+  bool isOutOfWater() const { return y < 5; }
 
   void update();
-  void draw();
+  void draw() const;
 };