Coley had a crash during his first qualifying run of the day but managed to get the boat running again.
Australian Superboat champion Greg Crusty Mercier had mechanical problems and did not get into his stride.
Sam Newdick (Hamilton) and Glen Mason won their second final in a row in PSP Group A with 53.65.
Aussie Paul Gaston came a narrow second, 53.91, with Richard Murray (Wanganui) taking third.
In the entry level JetPro 400 class Brett Thompson (Piopio) and Megan Brodie took their second final in a row, 58.41, ahead of Warren Farr (Taupo), 58.87, and Patrick Haden (Otorohanga), 59.35.
Whilst fine, hot conditions prevailed, a fault with the timing system and a leak in the track caused some problems.
The crews have a break until the third round at the Meremere Sprint Bowl on August 24.
Points: Suzuki Superboat Championship: Peter Caughey (Canterbury) 59 points, Leighton Minnell (Wanganui) 58 points, Steve Bron (Feilding) 54 points.
PSP Group A Championship: Sam Newdick (Hamilton) 60 points, Richard Murray (Wanganui), Paul Gaston (Queensland) 57 points, Bevin Muir (Thames) 52 points.
JetPro 400s: Brett Thompson (Piopio) 60 points, Warren Farr (Taupo) 55 points,
Gerry Linklater (Wanganui), Patrick Haden (Otorohonga) 53 points.