🔍 Key Concepts

• Difference between wet-type and dry-type diesel exhaust systems • Purpose of a spark arrestor in preventing fire hazards • Which exhaust systems discharge hot, dry gases versus cooled, water-mixed gases

💭 Think About

• Which type of exhaust has the greatest risk of emitting hot sparks that could ignite nearby combustible material? • How does mixing seawater with exhaust gases change their temperature and ability to carry burning carbon particles? • Think about which exhaust systems are more often used on small workboats and vessels operating near flammable structures or vegetation.

✅ Before You Answer

• Identify which muffler type produces very hot, dry exhaust likely to carry sparks • Confirm which muffler type mixes cooling water with exhaust gases, greatly reducing spark risk • Match the highest fire risk exhaust type with the one most likely to be fitted with a spark arrestor