Crew transportation executed by vessels started as a result of the development of offshore platforms close to land. Due to the growing oil demand in combination with limited space for new installations in shallow water areas, these platforms have expanded to deepwater locations. To transport crew over these longer distances, helicopters are used nowadays. Offshore crew transportation is driven by cost, safety, comfort, speed, workability, logistical solution, integrated solution, resilient solution and reputation. An assessment of these concludes that vessels can compete with helicopters for crew supply in the offshore market. Subsequently, an analysis to understand the performances of existing Crew Transfer Vessels competing with helicopters, results in the identification of a market gap: vessels that can operate in mild sea conditions and sail long distances at high speed. This research aims to develop a concept design for a Fast Crew Supplier (FCS) that fits the market gap while scoring better relative to helicopters on the combination of cost, safety, comfort, and speed. The selection of the vessel design requirements is based on detailed characteristics of West Africa, the Mexican Gulf of Mexico and the Middle-East. Main design requirements for the concept design are the significant wave height between 1.5 and 2 meters, speed between 35 and 40 knots, personnel capacity between 80 and 150 and a range of 1200nm. Since the vessel has to transfer and transport personnel, it should perform well at zero and at high speed. In addition to the above described criteria, the hull design and its dimensions have the most influence on the goal of the concept design, according to the elaborated House of Quality (HoQ). Hull-types considered for the design are the mono-hull, catamaran, trimaran, SWATH, hydrofoil, WIG and ACV. With the use of literature research, the seakeeping analysis program (SHIPMO) and costs calculated, the most attractive hull design relative to the boundary conditions has been defined the mono-hull. This was possible by processing the results into unitless measures using elements of the Multi-Attribute Utility Theory (MAUT) Optimal dimensions are determined after an iterative process of the arrangements of the vessel in combination with stability characteristics. In this, the calculation and evaluation of the longitudinal centre of gravity (LCG) and the metacentric height (GM) have played a major role. The final length is 51m, and the final beam is 8.2m, which results in the concept design FCS 5108. According to the results of speed, range, significant wave height and cost, the FCS 5108 fits the market gap. Comparing the FCS 5108 to a helicopter as crew transportation to an offshore field with three platforms in West Africa, the concept design is considered significantly more cost-effective, safer, more comfortable, and fast enough. To conclude, the FCS 5108 fits the market gap and scores better on the combination of the four design drivers relative to helicopters. For the further development of this concept design, it is recommended for Damen to continue in the Systems Engineering Approach and Design Spiral.