“Fixed” refers to the fact that the keel isn’t removable. It’s either part of the boat’s hull, or it’s bolted on and can’t be removed without dry-docking the boat.
There are some boat designs with removable keels. For instance, many small sailboats (called a dinghy) have removable keels, so you can remove the keel and beach them easily. The downside to having a removable keel on a sailboat is that it makes the boat prone to capsizing in strong winds; A fixed keel can have a built in ballast to keep the boat from tipping. But on a dinghy, you need to use a live ballast (literally your own body weight leaning out of the boat) to counteract the wind’s effects.
“Fixed” refers to the fact that the keel isn’t removable. It’s either part of the boat’s hull, or it’s bolted on and can’t be removed without dry-docking the boat.
There are some boat designs with removable keels. For instance, many small sailboats (called a dinghy) have removable keels, so you can remove the keel and beach them easily. The downside to having a removable keel on a sailboat is that it makes the boat prone to capsizing in strong winds; A fixed keel can have a built in ballast to keep the boat from tipping. But on a dinghy, you need to use a live ballast (literally your own body weight leaning out of the boat) to counteract the wind’s effects.
Isn’t a non weighted and removable „keel” on small sailing dinghies called a „dagger board” and is there only for mitigating drift?
That’s some fun stuff though, especially on a catamaran when one of the two hulls is entirely is up in the air.