What is a bilge pump? Quite simply, it is a pump placed in the the bilge of a boat (the area inside the hull) to pump out water that collects there.
Why does water collect in the bilges and why is it important to get rid of it? Water can come to the bilge from a variety of different places; rain water, wash down water from cleaning the decks, coolant water occasionally drains into the bilges and even just minor leaks and drips from shaft and prop glands or hoses.
An excess amount of water in the bilge can lead to your boat sitting lower in the water, risk flooding or even in the very worst scenario sinking.
Picking a bilge pump right for you is going to be down to the size of your boat and the space you have to mount it in the bilges.
Smaller boats can make do with smaller bilge pumps or even manual bilge pumps. Larger vessels, or boats that spend a lot of time offshore may go for a combination of bilge pumps - small electric bilge pumps, or a manual pump to deal with the incidental water that collects in the bilges and a larger high capacity pump to use in the event of an emergency.
It is important to note that there isn't a bilge pump that will likely stop a boat from sinking should you get a hole in the hull, but it could buy you the time to repair it or put out a mayday call and exit the vessel safely.