Many yacht owners and captains are currently looking for an exhaust system upgrade to replace the original dry silencer unit with SCR (selective catalytic reduction, IMO TIER III) and/or DPF (Diesel Particle Filter) solutions. For a seamless integration into your original exhaust system it would be best to contact the original supplier. They have all the information and data you require to check what is possible and what not. The supplier can also give advice on which options you have and what type of upgrade would fit inside the current system in terms of available space and backpressure, temperature and noise & vibration levels.
Exhaust upgrades with additional aftertreatment systems will have a major effect on the working principle of the original exhaust system. To avoid issues between you and the aftertreatment supplier we strongly advise first checking with your current partner.