Trim Tabs Princess V39

Why bother remembering, when you can see in the video that she's running at exactly 3500?
3,3 liters/Nm is not bad either. (y)

PS for 47GC: you weren't possibly running with a 3kts tide, or were you? :D
 
Weight , the tank levels and other accumulation of cruising stores will have a bearing .Also if the props are as new or even 1 week in the sea at the dock a microscopic level of crud will take the out of the box shine off them .

The trim gauges might not be exactly identical between the two boats , so one the slower might copy the faster boats numbers to try and match , but because of the difference in calibration its drives are not the same angle despite the dash gauges saying so .

Reduce the lard , use out of the box factory as fresh as you can props and play around with the drive trim angles .

Also even if they have the same 330 s - there’s ambient air temp and intercooler efficiency, or cleanliness to factor in .

Loch ness and SoF = huge ambient temp diff .
 
Portofino said:
Loch ness and SoF
Click to expand...
How can you tell, did you recognize Loch Ness from the video?
Anyway, that would make the speed achieved even more remarkable.
Boats goes slightly faster in salt rather than fresh water, not the other way round.
 
MapisM said:
How can you tell, did you recognize Loch Ness from the video?
Anyway, that would make the speed achieved even more remarkable.
Boats goes slightly faster in salt rather than fresh water, not the other way round.
Click to expand...

That is actually true. But the warmer temperatures in the Med can result in a loss of speed of about 10%.
I know of quite a few boats which never saw the speed they saw in the UK when tested again in the Med.
Loss of 2 knots is pretty normal.....
 
MapisM said:
How can you tell, did you recognize Loch Ness from the video?
Anyway, that would make the speed achieved even more remarkable.
Boats goes slightly faster in salt rather than fresh water, not the other way round.
Click to expand...
Loch Lomand , a typo .
Its the Scottish one thats quicker than the SoF one , and the air density thing that trumps your sea water / vs Fresh buoyancy point .
After all why bother after cooling if was made a piffling % difference and ambient air hotter in the summer SoF is gonna rob the SoF one of power .Remember diesels are glorified air pumps and some bright spark ( wrong pun I know ) decided to squirt oil in and it ignited .Rudolf something or other his surname began with a D :) .

I see “ charge air temp “ on the MMDS .Two factors .1 the ambient starting temp could be 18 in a morning start or 34 up anchoring to return to port .Similarly the sea temp being pumped round ( goes to the CAC first ) also rises as the season progresses.currently 25 off Liguria, but I have seen 30 after prolonged calm , high pressure sun dawn till dusk for 7 days .
A storm or white horse waves stirs it up and it drops back to 25 ish .

Those are the head winds decreasing the air density of the CAC .

I haven’t been out in anger in January with air temps 8 and sea 12 .Nor likely .

The loch temp in Scotland …..well you need neoprene to swim in it .A Summers day can be ^ those sort of temps btw .
 
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Yeah, she’s berthed at Loch Lomond. New props fitted in April, fresh hull etc. I’m quite impressed with the speed. Just need to suss out the trimming and I’ll be a happy boy.
 
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