Fellow Whanganui driver Richard Murray has also shown steady improvement after some tinkering under the hood, currently in fourth overall.
In the Fowler Homes Group A class, Whanganui's Ross Travers will likely have to be content to finish third overall for the season, as he sits 9-11 points behind Canterbury's Si Gibbon and Hamilton's defending champion Ollie Silverton, who will fight it out for the title.
Similar to Coley, Travers has been more focused on the end game – making alterations to his Radioactive boat in order to have it fully ready for the World Series in Australia later this year.
In the Stinger Boats Group B, Whanganui's former champion Hayden Wilson is eight points behind the top three, while expat Whanganui competitor Kellie Minnell is on her home track has a chance to overtake fellow Taranaki racer Daniel Reade in second place, although Te Awamutu's Patrick Haden should be safe to retain his national title.
Points standings
Superboats: 1. P Caughey 150; 2. R Coley 132; 3. N Berryman 128; 4. R Murray 121; 5. B
Gray 109.
Group A: 1. O Silverton 147; 2. S Gibbon 145; 3. R Travers 136; 4=. S Rice 112; 4=. A Ryan 112.
Group B: 1. P Haden 146; 2. D Reade 136; 3. K Minnell 133; 4. H Wilson 125; 5. J Simmons 119.