From left to right: The Attwood A750, the Rule Pro-Series 700, the Shurflo Piranha 800, and the Shurflo Bait Sentry 800.

Slurping and sucking hour after hour in the bowels of your boat, pushing corrosive salt water through its passages—that’s the life of a baitwell pump. Its sole purpose: Move clean oxygenated water into your bait tank and keep your precious cargo alive and healthy. Any mechanical breakdown, weak flow, or debris-induced blockages spell disaster. Live bait turns into dead bait, and you lose your chance to catch fish.

You should select a pump based on the size of your tank, number and kind of bait you carry, and the water temperature in your area. Here’s a good rule of thumb. Your pump should be able to fill your bait tank in…