A sport or pleasure fishing boat having a closed live well for holding a selected volume of water and a live well ventilation vent unit mounted in a top wall overlying well. The live well vent unit is an open ended elongate sleeve that projects through the wall into the well. There is a partition dividing the interior of the sleeve into first and second separate vertical disposed air flow passages. Baffles extend from the upper end of the partition and overlying a portion of the respective passages exposed to atmosphere. The baffles slope upwardly and outwardly away from the partition and terminate in a free outer edge spaced a selected distance from the adjacently disposed end of the sleeve. The space between the baffle and sleeve defines a crescent shaped opening for the flow of air there through. The free outer edge of the baffle is spaced vertically from the upper end of the sleeve to catch and deflect a current of air into the well above the water therein.