In the Group A Championship, Richard Murray hopes to lower the nine-point buffer to Hamilton's Sam Newdick, who is still the favourite as he hunts his fifth straight win.
Wanganui's best hope for a title is in the 400 class, where stock driver turned jetboater Gerry Linklater holds the lead in a division where five drivers are separated by only 12 points.
Tomorrow's round is the last before the championships return for their finale on April 13 at the Shelterview Jet Sprint Track in Wanganui.
Points after four rounds:
Suzuki Superboat Championship: Peter Caughey (Canterbury) 119, 1; Leighton Minnell (Wanganui) 109, 2; Pat Dillon (Wanganui) 105, 3. PSP Group A Championship: Sam Newdick (Hamilton) 120, 1; Richard Murray (Wanganui) 111, 2; Paul Gaston (Queensland) 107, Bevan Muir (Thames) 107, 3=. JetPro 400s: Gerry Linklater (Wanganui) 112, 1; Tim Edhouse (Owhanga) 102 points, 2; Brett Thompson (Piopio) 100, Warren Farr (Taupo) 100, Ray Thompson (Whangamata) 100, 3=.