12m displacement cat finally launched

Our Roger Hill designed 12 m displacement cat has had its first outing on theTauranga Harbour.

Driven by twin 170hp Hyundai diesels on conventional shafts, the craft notched up a top speed of 24 knots. The displacement mode created a strange sensation for those not used to a boat resisting the normal habit of wanting to plane when the power goes on. Its sharp bow cut effortlessly and extremely smoothly through the largest waves found on the day  – unfortunately just under a metre in the harbour entrance.

Latest performance data. Half fuel, full water tanks but minimal personal gear loading. Sea conditions – half metre chop.

• 8 knots, 9.6 litres per hour total both engines
• 11 knots, 16 litres per hour total
• 15 knots, 26.6 litres per hour total
• 20 knots, 43 litres per hour total
• 24 knots, 70 litres per hour total.

For the 60 nautical mile trip from Auckland to Great Barrier Island or Tauranga to Great Mercury Island, cruising at 15 knots would take 4 hours and use 106.4 litres of diesel at today’s cost of about $81!

At 20 knots it would be a 3 hour trip at a cost of $100. (Diesel at $0.77 per litre). Please note sea conditions and boat loading will influence this data.