## 1 Introduction  
Evacuation refers to a temporary but rapid relocation of people, individually or in an organized manner, from a threatened or disaster area to a safe place as a rescue or precautionary measure [1]. In comparison with any other kind of evacuation, ship evacuation in an emergency is vital in the occurrence of an accident on the vessel and presents a number of differences in several aspects. It can be described as a process that follows the decision of the commanding officer to abandon the ship for the safety of the passengers and crew and is the last resort in case of emergency. In the case of a critical incident onboard that requires mustering, evacuation and abandonment of the ship, an evacuation alarm is sounded through the PA system and the crew organizes the orderly assembly of passengers to the muster stations. Once the decision for ship abandonment has been taken, the crew organizes the transfer of passengers to the embarkation stations and prepares the LSAs and survival crafts for embarkation and launching. In this process, crew members follow the established procedures and guidelines, providing instructions to passengers and facilitating their movement to the designated stations, as described in the MSC/Circ. 699 Revised Guidelines for passenger safety instructions [2]. The capacity and the size of large passenger ships has increased in the last decade, leading to cruise ships with a capacity of over 6000 passengers and 2000 crew members, over 220,000 GRT and a cruise size of over 300 m and 16 decks [3]. Modern cruise ships are organized much like floating hotels and feature amenities such as theaters, restaurants, spas, fitness facilities, casinos and even amusement park attractions. Consequently, the evacuation of large passenger ships with thousands of people moving inside the ship is a complicated, safety-critical and time-restricted task that involves complex decision making based on an evolving situation [4]. A crucial aspect in ship evacuation is the information that is available to passengers onboard concerning the safety and emergency protocols, usually leaflets in cabins or at corridors and, in some cases, videos available on the in-cabin television system [5]. In addition, passengers receive a safety briefing and take part in muster drills prior to departure so as to get familiar with the safety procedures during an evacuation, as mandated by the SOLAS Convention. During these emergency drills, the general emergency alarm is activated, followed by safety announcements to passengers from the captain while crew members instruct passengers to proceed to their muster stations and are informed on how to put on their lifejackets. While muster drills can improve preparedness in case of emergency, real-life evacuation appears to be more complex and challenging for the passengers to cope with [6; 7; 8]. Extensive and continuous effort is being made to develop evacuation models with the aim to predict the real time needed to evacuate a ship and the optimal evacuation routes [9; 10; 11; 12; 13]. This is anything but a trivial task due to the need to deal with human factors that are hard to analyze. These include moving disabilities, age, sex and physical condition, as well as the psychological effects of a distress situation on a person and their ability to effectively navigate towards the mustering point or embarkation deck. A passenger may be required to move to the other side of the ship and/or another deck. Moreover, the ship evacuation process can become even more complicated, challenging and stressful in the presence of smoke, fire or flooding incidents, substantial ship motions and inclination and bad weather conditions, which in turn can decrease their ability to comprehend the crew instructions and public announcements, while reducing the visibility of static exit signs.These models lead to ship designs that are easier and more timely to evacuate and to the selection of optimal evacuation routes.