jack_patricia
Well-known member
- Joined
- Nov 13, 2022
- Messages
- 63
- Fluid Motion Model
- C-32 C
I just delivered our new-to-us 2022 Cutwater 248 to SW Florida from Jacksonville, where we purchased her. It was the first trip I made in the boat, was disappointed with its fuel efficiency (but maybe shouldn't be), and I'm hoping some of you will comment on how I did the run and what I can/should do differently.
I ran the boat 20 to 27 knots (about 4500 - 5200 rpm), all in protected waters of about 250 miles. The boat has a clean hull, a 100 hr Yamaha 250 and the stock prop. We ran with a light load: 20 gals water, tools, some food & galley gear, and me. The Yamaha display consistently showed a fuel burn of 1.2 NMPG (let's say 1.4 statute MPG) with only fleeting improvements to 1.4 NMPG. My hand calculations at fuel stops showed the same, let's say 1.25 NMPG (1.45 MPG). I ran with the leg down (no trim up) and most or all of the tabs. Using the tabs obviously hurt fuel efficiency but they helped the boat come up on plane, kept the bow down at speed, and the boat simply seemed happier. I actually came away wondering if I should add those small vertical fins to the tabs sides to improve their contribution. Now it's time to begin experimenting. I'm new to powerboats and planing, and will surely benefit from some coaching in this area. So I welcome your comments on this, including A's to the following Q's:
1. Is this level of fuel efficiency typical for C24's in smooth'ish waters?
2. What recommendation(s) do you have for trimming the leg? What do you think of how I used the tabs?
3. If loading the boat up somewhat - let's say for a multi-day trip for the two of us - would you expect fuel efficiency to change much?
4. For this model, what's the thinking about adding those small vertical fins to the trim tabs?
Thanks for offering whatever thoughts you'd care to share.
I ran the boat 20 to 27 knots (about 4500 - 5200 rpm), all in protected waters of about 250 miles. The boat has a clean hull, a 100 hr Yamaha 250 and the stock prop. We ran with a light load: 20 gals water, tools, some food & galley gear, and me. The Yamaha display consistently showed a fuel burn of 1.2 NMPG (let's say 1.4 statute MPG) with only fleeting improvements to 1.4 NMPG. My hand calculations at fuel stops showed the same, let's say 1.25 NMPG (1.45 MPG). I ran with the leg down (no trim up) and most or all of the tabs. Using the tabs obviously hurt fuel efficiency but they helped the boat come up on plane, kept the bow down at speed, and the boat simply seemed happier. I actually came away wondering if I should add those small vertical fins to the tabs sides to improve their contribution. Now it's time to begin experimenting. I'm new to powerboats and planing, and will surely benefit from some coaching in this area. So I welcome your comments on this, including A's to the following Q's:
1. Is this level of fuel efficiency typical for C24's in smooth'ish waters?
2. What recommendation(s) do you have for trimming the leg? What do you think of how I used the tabs?
3. If loading the boat up somewhat - let's say for a multi-day trip for the two of us - would you expect fuel efficiency to change much?
4. For this model, what's the thinking about adding those small vertical fins to the trim tabs?
Thanks for offering whatever thoughts you'd care to share.