Livewell
A water tank on fishing boats to keep bait and catch alive.
A livewell is a tank on fishing boats designed to hold live bait and caught fish. It functions by drawing in water from the surrounding body and using an air pump to aerate it. This feature is common on modern sport fishing boats and yachts, particularly those used in tournaments, where fish must stay alive and in their caught condition until the boat reaches the dock for weighing.
A general guideline for sizing a livewell is to provide one gallon (3.8 liters) of water for every inch of fish length to keep them alive for extended periods. Beyond size and water circulation, maintaining a temperature below 75 °F (24 °C) and removing metabolic waste are critical. Ice can be used to cool the water.
Oxygen levels must stay above 5 parts per million. Electric aeration systems, which create a spray to increase water surface area or use a Venturi effect, are common. A livewell is essentially a box for transporting live aquatic animals—shrimp, baitfish, or mature fish, in saltwater or freshwater. It should be made of non-toxic materials and can be square, rectangular, oval, or round. It may be insulated, portable, and equipped with a drain and lid.
Maintaining safe water quality is essential for the animals’ habitat during transport. Dissolved oxygen saturation is the most important parameter to control when moving baitfish, shrimp, or mature fish. Oxygen-injection systems, including LOX systems, enrich the water with pure 100% compressed welding oxygen, using a precision regulator, tube, and diffuser. These systems are designed for loads from 1 pound to over 1,000 pounds, ensuring 100% DO saturation or higher.
The EPA’s minimal safe standard for steady-state environments is 5 ppm DO. For bass, dissolved oxygen is the key factor. At 70 °F, 100% saturation equals 8.8 mg/L; at 80 °F, it is 7.9 mg/L—both suitable for keeping bass alive. Without oxygen injection, it is difficult to supply enough oxygen for heavy tournament limits. Texas Parks and Wildlife Department hatcheries have long used oxygen injection to hold fish at ratios of one pound per gallon. However, boat manufacturers do not offer oxygen injection systems as standard options. Proper installation and operation of such a system can keep oxygen levels above the preferred 7 mg/L, even with heavy loads.
- Rule of thumb for size
- Every inch length of fish needs a gallon (3.8 liter) of water for prolonged survival
- Maximum water temperature
- Below 75 °F (24 °C)
- Minimum dissolved oxygen level
- 5 parts per million (EPA standard for steady state environments)
- Preferred oxygen level with injection
- Above 7 mg/L
- Oxygen saturation at 70f
- 8.8 mg/L at 100 percent saturation
- Oxygen saturation at 80f
- 7.9 mg/L at 100 percent saturation
- Transport ratio used by tpwd hatcheries
- One pound of fish to a gallon of water or greater
Lore & Background
A livewell is a box used to transport live aquatic animals, including shrimp, baitfish, and mature fish, for both saltwater and freshwater species. It should be made of non-toxic materials and may be square, rectangular, oval, or round. The box can be insulated, portable, and have a drain and lid. Key factors for functionality include size, water circulation, maintaining proper temperature, and removing metabolic waste. Water temperatures should be kept below 75 °F (24 °C), and ice can be used as a coolant.
Maintaining adequate oxygen levels is critical, with dissolved oxygen being the single most important factor for keeping bass alive. Electric aeration systems are often used, creating a spray to increase water surface area or passing water through a Venturi. Without injecting oxygen, it is very difficult to supply enough oxygen for heavier tournament limits. Oxygen injection systems, including pure 100% compressed welding oxygen with a precision dose adjustable regulator, are used to ensure 100% DO saturation or greater, even with fish loads from 1 lb to over 1000 lbs.
Oxygen injection has long been used by Texas Parks and Wildlife Department (TPWD) hatcheries to maintain fish health during stocking. Fisheries staff regularly transport or hold fish in ratios equal to or greater than one pound of fish to a gallon of water. However, boat manufacturers do not offer oxygen injection system options as standard.
Reader's Guide
The livewell is significant in sport fishing and tournament contexts because it allows caught fish to be kept alive and in the condition they were caught until the boat returns to dock for weighing. Its design must balance several factors: size according to the rule of thumb (one gallon per inch of fish), water circulation, temperature control below 75 °F, and removal of metabolic waste. The most critical water quality parameter is dissolved oxygen saturation, which must be maintained above 5 ppm, with a preferred level of 7 mg/L when using oxygen injection. At 70 °F, 100 percent oxygen saturation is 8.8 mg/L; at 80 °F, it is 7.9 mg/L, both suitable for keeping bass alive. Without oxygen injection, supplying enough oxygen for heavy tournament limits is very difficult. The legacy of livewells includes their use by hatcheries like TPWD for transporting fish at high densities, though boat manufacturers do not offer oxygen injection systems. Proper installation and operation of such systems ensure oxygen levels remain above the preferred threshold even with heavy fish loads.
Did You Know?
- A rule of thumb is that every inch of fish needs a gallon (3.8 liters) of water for prolonged survival in a livewell.
- Water temperatures in a livewell should be kept below 75 °F (24 °C); ice can be used as a coolant.
- Texas Parks and Wildlife Department hatcheries have long used oxygen injection to transport fish at ratios of one pound of fish per gallon of water or greater.
Frequently Asked Questions
What is a Livewell?
A Livewell is a dedicated tank mounted on a fishing vessel that keeps both live bait and freshly caught fish alive until the angler returns to shore. It is a standard fixture on modern sport-fishing boats and yachts.
How does a Livewell function?
The system draws in surrounding water and pushes it through an air pump to keep oxygen circulating. This continuous flow prevents the water from going stagnant and keeps the fish in an active, healthy state.
What's the golden rule for sizing a Livewell?
The widely cited guideline is to allocate one gallon (about 3.8 liters) of water for every inch of fish length if you want them to survive for an extended period. Dropping below that ratio risks crowding, stress, and loss.
What temperature and oxygen levels should a Livewell maintain?
Water should stay below 75 °F (24 °C), and dissolved oxygen must never fall under 5 ppm to meet basic survival standards. When an injection system is in use, anglers aim for above 7 mg/L to keep fish in peak condition.
Why is a Livewell critical in tournament fishing?
Tournament rules require caught fish to remain alive and in their natural caught condition until they reach the dock for official weighing. A properly running Livewell is what makes that requirement actually possible.
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