diff --git a/src/boat.py b/src/boat.py
index 7a480ed..c7e8c81 100644
--- a/src/boat.py
+++ b/src/boat.py
@@ -2,7 +2,13 @@
 import statistics
 from custom_exception.nothing_to_compare_error import *
 
+
+
 class Boat:
+    """
+    Representation of a boat.
+    A boat is defined by its name, ids, url, avatar, temperatures ans positions in the sea.
+    """
     def __init__(self, boat_id: str, name: str, sismer_id: str, url: str, avatar:str , temperatures: list, positions: list):
         self.boat_id = boat_id
         self.name = name
@@ -12,17 +18,27 @@ class Boat:
         self.temperatures = temperatures
         self.positions = positions
     def __str__(self):
-        return f"{self.name}"
-    def __eq__(self, other):
-        if other is None:
-            return False
-        if not isinstance(other, self.__class__):
-            return False
-        return self.boat_id == other.boat_id
+        """
+        When a Boat goes to string, the returned value is simply the name of this Boat.
+        """
+        return self.name
+        def __eq__(self, other):
+            if other is None:
+                return False
+            if not isinstance(other, self.__class__):
+                return False
+            return self.boat_id == other.boat_id
 
     def get_temp_mean(self):
-        return statistics.mean(list(filter(None, self.temperatures)))
+        """
+        Process the average of temperatures with None values removed.
+        """
+        return statistics.mean(list(filter(lambda v: v is not None, self.temperatures)))
     def get_northiest_coords(self):
+        """
+        From all positions send by the boat, return the one on the northiest.
+        Will raise a NothingToCompareError if the boat has no position saved
+        """
         if len(self.positions) == 0:
             raise NothingToCompareError(f"{self.name} must have coords to compare")
         best = self.positions[0]
@@ -32,4 +48,7 @@ class Boat:
         return best
                 
     def print_details(self):
+        """
+        Print the Boat with more details than __str__
+        """
         print(f"[{self.name}({self.boat_id})]\nSISMER ID: {self.sismer_id}\nURL: {self.url}\nAvatar: {self.avatar}")
diff --git a/src/boats_loader.py b/src/boats_loader.py
index bbf64e3..5e2d168 100644
--- a/src/boats_loader.py
+++ b/src/boats_loader.py
@@ -1,5 +1,8 @@
 #coding:utf-8
 
 class BoatsLoader:
+    """
+    Interface for all classes which wants to load boat
+    """
     def load_boats(year: int):
         pass
diff --git a/src/fleet.py b/src/fleet.py
index 82bc6b0..dad36b6 100644
--- a/src/fleet.py
+++ b/src/fleet.py
@@ -12,15 +12,21 @@ class Fleet:
         
 
     def compare_boats(self, getter: callable, comparator: callable):
+        """
+        Compare each boat with dynamic parameter
+        getter: This callable must be a methode from Boat and must have no parameters. It will allow to select data to compare.
+        comparator: This callable must have its twp parameters's type the same that the one return by getter. It will allow to compare data each other
+        """
         if len(self.boats) == 0:
             raise NothingToCompareError("No boats to compare")
         best_boat = None
         best_element_to_compare = None
         for boat in self.boats:
             try:
-                if comparator(getter(boat), best_element_to_compare):
+                data = getter(boat)
+                if comparator(data, best_element_to_compare):
                     best_boat = boat
-                    best_element_to_compare = getter(boat)
+                    best_element_to_compare = data
             except StatisticsError as e:
                 continue
             except NothingToCompareError as e:
@@ -28,12 +34,14 @@ class Fleet:
         return best_boat, best_element_to_compare
 
     def get_northiest(self):
-        try:
-            return self.compare_boats(Boat.get_northiest_coords, Position.is_norther_than)
-        except TypeError as e:
-            print(e)
-            return None, None;
+        """
+        Returns the boat which went the northiest and its coords.
+        """
+        return self.compare_boats(Boat.get_northiest_coords, Position.is_norther_than)
     def get_highiest_heat_mean(self):
+        """
+        Returns the boat which saved the highiest heat average and this average.
+        """
         return self.compare_boats(Boat.get_temp_mean, float.__ge__)
         
 
diff --git a/src/main.py b/src/main.py
index ccf6bc4..df11bb7 100644
--- a/src/main.py
+++ b/src/main.py
@@ -3,19 +3,34 @@
 from sys import argv
 import fleet
 from rest_api_boats_loader import RestApiBoatsLoader
-import custom_exception
 
+# If the year give by user. if not print a message and exit
 if len(argv) <= 1:
-    raise custom_exception.MissingEntryArgumentError("You must give the year you want to get")
-year = int(argv[1])
+    print("You must give the year you want to get (eg. python3 main.py 2021)")
+    exit(1)
 
+# Is the argument given a number. If not print a message and exit
+try:
+    year = int(argv[1])
+except ValueError:
+    print("The year must be a number")
+    exit(1)
+
+# fleet loading with data from the year
 my_fleet = fleet.Fleet(year, RestApiBoatsLoader())
+
+# Print detail for each boat from the fleet
 for boat in my_fleet.boats:
     boat.print_details()
     print()
+
+# get the boat which went the northiest
 northiest_boat, northiest_coords = my_fleet.get_northiest()
+
+# get the boat which have the highiest heat average saved
 hottiest_boat, heat_mean = my_fleet.get_highiest_heat_mean()
 
+# Prints results
 if northiest_boat is None:
     print(f"No data to find the northiest boat for {year}")
 else:
diff --git a/src/position.py b/src/position.py
index 50abbb6..4a1f6ee 100644
--- a/src/position.py
+++ b/src/position.py
@@ -1,6 +1,9 @@
 #coding:utf-8
 
 class Position:
+    """
+    Position's representation: [<latitude>; <longitude>]
+    """
     def __init__(self, latitude: float, longitude: float):
         self.latitude = latitude
         self.longitude = longitude
@@ -8,6 +11,9 @@ class Position:
     def __str__(self):
         return f"[{self.latitude}; {self.longitude}]"
     def is_norther_than(self, position):
+        """
+        Is the current instance of postition norther than <postition>
+        """
         if position == None:
             return True
         return self.latitude >= position.latitude
diff --git a/src/rest_api_boats_loader.py b/src/rest_api_boats_loader.py
index 5320c04..e984426 100644
--- a/src/rest_api_boats_loader.py
+++ b/src/rest_api_boats_loader.py
@@ -5,14 +5,20 @@ from position import Position
 from boats_loader import BoatsLoader
 import requests
 
-class RestApiBoatsLoader(BoatsLoader): 
+class RestApiBoatsLoader(BoatsLoader):
+    """
+    Allows to load Boats from https://localisation.flotteoceanographique.fr/api/v2/vessels
+    """
     def __init__(self):
         self.url = 'https://localisation.flotteoceanographique.fr/api/v2/vessels'
         self.search_begin = '-01-01T00:00:00.000Z'
         self.search_end = '-12-31T23:59:59.000Z'
 
-
+    
     def load_boats(self, year: int):
+        """
+        Create and return Boats with Loaded data fom flotteoceanographique.fr
+        """
         raw_data = self.load_from_url(self.url)
         boats = []
         for boat in raw_data.json():
@@ -20,7 +26,12 @@ class RestApiBoatsLoader(BoatsLoader):
             tmp_boat = Boat(boat['id'], boat['name'], boat['sismerId'], boat['url'], boat['avatar'], boat_data['temp'], boat_data['pos'])
             boats.append(tmp_boat)
         return boats
+
     def _load_boat_data(self, boat_id: str, year: int):
+        """
+        Collects all positions and sea temperatues send by <boat_id> in <year>.
+        Return a Dictionary with 2 keys: 'pos' and 'temp'
+        """
         json_data = self.load_from_url(self.url + f"/{boat_id}/positions?startDate={year}{self.search_begin}&endDate={year}{self.search_end}").json()
         data = {}
         data['pos'] = []
@@ -35,6 +46,9 @@ class RestApiBoatsLoader(BoatsLoader):
         return data
     
     def load_from_url(self, url: str):
+        """
+        Send a GET request to <url> and convert result in Response (see requests module)
+        """
         data = requests.get(url)
         if(data.status_code != 200):
             raise custom_exception.HttpException(f"Error {data.status_code}")