diff --git a/src/app/model/vessel.ts b/src/app/model/vessel.ts
index 070f33e..5d56693 100644
--- a/src/app/model/vessel.ts
+++ b/src/app/model/vessel.ts
@@ -2,13 +2,16 @@ import {Message} from './message';
 
 export class Vessel {
   messages: Array<Message>;
+  firstAppearance: number;
 
   constructor(messages: Array<Message>) {
     this.messages = messages;
   }
 
   addMessage(message: Message): void {
-  this.messages.push(message);
+    this.messages.push(message);
+    this.determineFirstAppearance(message);
+
   }
 
   getMMSI(): string {
@@ -26,4 +29,11 @@ export class Vessel {
     return '#' + (+this.getMMSI()).toString(16).substr(0, 6);
   }
 
+  determineFirstAppearance(message: Message): void {
+    const timeInS = Date.parse(message.time) / 1000;
+    if (this.firstAppearance > timeInS) {
+      this.firstAppearance = timeInS;
+    }
+  }
+
 }
diff --git a/src/app/model/vessels.ts b/src/app/model/vessels.ts
index fea6cef..3a6572a 100644
--- a/src/app/model/vessels.ts
+++ b/src/app/model/vessels.ts
@@ -3,7 +3,6 @@ import {Message} from './message';
 
 export class Vessels {
   vessels: Map<number, Vessel>;
-  firstAppearance: number;
 
   constructor() {
     this.vessels = new Map<number, Vessel>();
@@ -13,14 +12,8 @@ export class Vessels {
     if (!this.vessels.get(Number(message.mmsi))) {
       this.vessels.set(Number(message.mmsi), new Vessel(new Array<Message>()));
     }
-    this.determineFirstAppearance(message);
     this.vessels.get(Number(message.mmsi)).addMessage(message);
   }
 
-  determineFirstAppearance(message: Message): void {
-    const timeInS = Date.parse(message.time) / 1000;
-    if (this.firstAppearance > timeInS) {
-      this.firstAppearance = timeInS;
-    }
-  }
+
 }