markpierce
Master and Commander
- Joined
- Sep 25, 2010
- Messages
- 12,557
- Location
- USA
- Vessel Name
- Carquinez Coot
- Vessel Make
- penultimate Seahorse Marine Coot hull #6
oops duplicate post
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Especially if the torque peek is quite flat .. and many are. I choose my engine mostly for it's power suitability. Do'nt even remember the torque curve.
Eye,
7 to 20 knots?
I'd call it closer to 10 to 14.
If you're going 7 or 20 knots you've got the wrong boat.
Just because a boat can do something dos'nt mean you should do it. Especially over long periods of time.
Many of us have the wrong boat but it's expensive to change.
Your fuel economy is not at a max. It continues to improve as your speed drops. At least mine does down to 4.8 kt at 1000RPM (the lowest I've measured).What happened to the old saying run 1 knot below hull speed which is the square root of (1.35 x waterline length) - your fuel economy is at its max and this is also your cruising speed ??? Or am I living in the past ??
Band, what's your strategy to avoid skin cancer? How's your berthing and cooking accommodations?
Your fuel economy is not at a max. It continues to improve as your speed drops. At least mine does down to 4.8 kt at 1000RPM (the lowest I've measured).
Richard
Frequent debate, time vs money. Bay Pelican gets 4mpg at 6.5 kts and 2.5mpg at 7.5 kts.
We pay Caribbean prices for diesel, perhaps $5 US per US gallon.
On an 80 mile run, the time difference is an hour and a half while the cost difference is $60 US.
Eye,
7 to 20 knots?
I'd call it closer to 10 to 14.
If you're going 7 or 20 knots you've got the wrong boat.
Just because a boat can do something dos'nt mean you should do it. Especially over long periods of time.
Many of us have the wrong boat but it's expensive to change.
ranger42c wrote;
"Wrong is in the eye of some beholders"
Good one Chris.
However your mood has nothing to do w what the designer intended for the boat. You could go 6 knots w a guided missile cruiser to take it to a greater extreme. Of course you can run 6 knots and call it one of your cruising speeds but no knowledgeable person will say the boat was designed for that speed to go from point A to point B. Moving about in a harbor yes, point ATo point B no. A to B is cruising.
ranger42c wrote;
"Wrong is in the eye of some beholders"
Good one Chris.
However your mood has nothing to do w what the designer intended for the boat. You could go 6 knots w a guided missile cruiser to take it to a greater extreme. Of course you can run 6 knots and call it one of your cruising speeds but no knowledgeable person will say the boat was designed for that speed to go from point A to point B. Moving about in a harbor yes, point ATo point B no. A to B is cruising.
However you would have dificulty finding a boat that was designed for 6-24 knots. How much time you spend at 6 knots is an element here. If you spend 75% of your time at 6 knots I'd say you do'nt need a 24 knot cruising speed. I'm not saying not to do it .. just that the boat was'nt designed for that. Not at all.
Eye,
7 to 20 knots?
I'd call it closer to 10 to 14.
If you're going 7 or 20 knots you've got the wrong boat.
Just because a boat can do something dos'nt mean you should do it. Especially over long periods of time.
Many of us have the wrong boat but it's expensive to change.
One of the main requirements of the Moon River design was a sliding scale of speed to include 7 to 16K cruise ability. It is not 7 or 20K . It is a continuous scale of 7 to 20K. Most of my travel time is between 9 and 10K with a hull speed based on 46+ foot WL, hull speed of about 9.2K. I can select the speed based on comfort fuel burn or need to get some place or current and weather conditions. I am willing to pay for the luxury of the sliding scale which I perceive as a clear benefit over the FD boats I have owned in the past. Tony Flemming the man behind Flemming Yachts has a very similar take on cruising speed and has incorporated it into his SD boats. Yes this philosophy is not for the weak of wallet, On the other hand it is not overtly wasteful.
AusCan,
Yes the same.
Mitsubishi S4L2 engine.
My cruise is 6.15 at 2300rpm. WOT 2950. Wish it was 3050.
I'm using a little more power I think probably due to weight. Willy is 8 tons.
But if one is regularly running a boat under or above the designers intent the question of "do I have the right boat" should emerge.