Seeing a 30- to 50-pound white seabass, or better yet, catching one like that, is part of the adventure of taking a half-day sportfishing trip out of Point Loma or Mission Bay. You never know what will tug the end of the line. And springtime means topwater time, the start of surface action for calico bass, barracuda and bonito or maybe a trophy yellowtail or white seabass.