Maritime shipping is the backbone of the world economy, accounting for more than 75 % of global trade by volume. At the same time, international shipping is responsible for 2-3 % of global greenhouse gas (GHG) emissions, similar to the worldwide air travel industry. Ships currently use fossil fuels to provide energy onboard. There are mainly two types of fuels in use. Heavy fuel oils or bunker oil comprise approximately 75% of all fuel use, while 23% of fuels are distillate diesel fuels, known as marine gas oil or marine diesel oil. The remaining 2% is dominated by LNG, but a few vessels also use LPG or methanol. The International Maritime Organization (IMO) aims to reduce total annual greenhouse gas emissions from international shipping by at least 50 % by 2050. Several strategies can be considered to reduce these emissions: fuel switching (hydrogen, ammonia, LNG, biofuels), electrification, and Carbon Capture and Storage (CCS). The CCShip project focuses on the onboard CCS to reduce emissions from shipping by investigating and developing different types of CO2 capture technologies (solvent, membrane, adsorption, etc.). Moreover, the project seeks to understand when CCS can be cost-competitive with alternative strategies such as fuel switching to ammonia or hydrogen. As the performance of CCS and its comparison with alternative strategies, this project's backbone consists of the development of shipping case studies that will serve as a basis for these evaluations. The goal of this paper is to present case studies representative of shipping case that have the most significant influence on emission production and the feasibility of installing carbon capture technologies onboard shipping.