Sea Chests

Sea chests can be an issue if boat is kept in areas with mussels. The constant water flow from ac pump allows them to grow inside box. They break off and ruin motors impeller when run after extended downtime. Will also clog coolers. Many boxes use very fine holes in ss plate bolted to outside of hull instead of traditional filters. Cleaner install and nothing to service. Builders have in some cases installed dedicated thru hulls for engines and used box for everything else.

You NEED to have the A/C pickup with it's own thru-hull. But many builders put it on the seachest and that created huge issues with marine growth. Seachests are good otherwise, but all of your water runs then have to be pulled from the one place the seachest is.

Great idea for a 900' ship. All the raw water is needed in the engine room so hose lengths are short and visible for replacement, the ship is always moving and the intake gets cleaned when needed. Those three characteristics are not always present in a yacht.

The yard will install the sea chest because it's easier and cheaper than individual sea-cocks. Then they run rubber hoses everywhere. Then they put bulkheads, flooring, equipment, and cabinetry over top of the rubber lines that will eventually need to be replaced.

The yacht will sit in a marina for months as the Air Cond pulls water through and growth increases. As soon as the engines start, the Air Cond cuts out because there's just not enough flow for everything at once and the captain is calling around for a diver to scrub the intake plate.

The builder will advertise that it's "Commercial Rated"!