On paper this game looks very promising but as the saying goes 'never judge a book by its cover' ... For starters the amount of hard drive memory the game uses up is enormous! Though Ship Simulator Extremes ran smoothly with no frame-rate issues the amount of memory used caused significant problems for me elsewhere on my PC. I also found the gameplay to be quite fractionated in terms of continuity mostly due to having to change terrains all the time in free roam (or Sandbox) mode.
There are only two terrains which allow realistic free roam experiences to the player. These are Bora Bora around which attention to detail is essential when selecting larger ships and the English Channel which allows Dover to Calais (and Isle of Wight) ferry crossings. So many of the others allow the player to navigate their way out of one of several huge real world ports ... Before having to change terrains which can only be done manually involving the rather disruptive selection process. The appearance of many of the ships also tends to be quite 'cartoony' rather than photo-realistic especially when viewed internally from the Bridge. There are some good points which mostly relate to the phenominal level of detail featured within each terrain. Also the DLC Content available through Steam greatly enhances the game in a number of ways: Especially the Ferries pack which was my favourite DLC download. Ship Simulator Extremes also features a built-in Mission Editor facility but it is strongly advised to read up on how to use this before attempting to do so.
Am I sad about this non-recommendation? Yes as Ship Simulator Extremes did genuinely appeal to me when I bought the game along with a number of the DLC downloads. But with so much hard drive memory required and generally fractionated and disrupted gameplay SSE receives a no-no from Me.