What Is the Best Cruising Speed when on Passage Offshore ?

[estarzinger]

We actually studied this question . . . and the answer is . . .

average cruising passage speed (kts) =
2.62 + 0.066*SA/D ratio + 0.051*LWL in feet

We looked at a lot of actual passage times from good sailors/cruisers and this formula comes +-10% most of the time.

[MarkJ]

Our average speed in normal crusing ie downwind.. is 140 miles per day.
A bad day would be 120 miles, and high speed day would be 150 miles.

The last few months we have been doing headwinds... and in then have average just 86 miles per day, week in week out. Woe! Thats just 3.6kts vmg.

The last week we copped a bit on the snoz and needed to motor sail. We were doing 2.7 knots and dropping the throttle back when it hitted 3 kts.
Our boat is really comfortable at that speed, and time isnt a problem because of our shift system, and it just sips fuel at low revs.

2.7 sounds awfully slow, but after a few years cruising the speed itself doesn't really matter. Its getting there in one piece, without having lost weight too much, breaking kit, breaking teeth, being happy and spankin' the chicky-babe on route that matters

if driving a boat at 8kts means fun for you, then think this: all the crap you hear about 8ktsd is ONLY downwind in optimal conditions. We heard a 70 foot biiiig boat exclaim on the HF net "We did a 200 mile day!!!!!!!!!!" well thats only 8.5 knots so if it was all that common people wouldnt bleat about it.

As for catamaras, well, sorry Dave, but if you want to check engine hours at the end of a voyage I'll put ours up next to a cat's any day. All I ever see if some bloke in his cat motoring along, sails furled... woman on the sat phone saying is don't heel...

[Chattcatdaddy]

Originally Posted by MarkJ

As for catamaras, well, sorry Dave, but if you want to check engine hours at the end of a voyage I'll put ours up next to a cat's any day. All I ever see if some bloke in his cat motoring along, sails furled... woman on the sat phone saying is don't heel...

lol...thats hilarious

[canuck1955]

Crusing speed should be slow and easy (5kts) and smell the roses along the way. If I want to get somewhere fast I like to cruise at about 450MPH on an "Air Canada" air yacht.
Sorry having problems with cruising and speed in the same sentence in a 'cruiser' forum.

[Ram]

When im not on a charter or going to pick one up I sail 90% of the time and have done a lot of 3.2 knots speeds for days on end, no hurry, no worry,no fuel or money spent

[Randyonr3]

Originally Posted by canuck1955

Crusing speed should be slow and easy (5kts) and smell the roses along the way. If I want to get somewhere fast I like to cruise at about 450MPH on an "Air Canada" air yacht.
Sorry having problems with cruising and speed in the same sentence in a 'cruiser' forum.

Must be comming from an "arm chair Sailor" .. Speed under sail is an essential ingredient to comfort and safety at sea.. The ability to make a fast passage reduces the time you're exposed to potentially bad weather or in the grip of an adverse current.. It also means making an anchorage on an unfamiliar coast befor dark, perhaps saving an anxious night watching..
being from the great white north, you know that when crap happens, it happens fast, and the run to cover is often the only way to save yourself and your boat.. smelling the roses has nothing to do with getting your butt to safety when it counts..

[s/v Jedi]

And so the posts about comfortable speed being dependent on boat length and displacement are happily ignored and the "who goes slowest must be the toughest" competition gears up again ;-)

ciao!
Nick.

[Randyonr3]

Originally Posted by s/v Jedi

And so the posts about comfortable speed being dependent on boat length and displacement are happily ignored and the "who goes slowest must be the toughest" competition gears up again ;-)

ciao!
Nick.

You bring up anothe good point Nick.... For years the general idea was to go as small as possible for the cost of outfiting the boat..which there are good issues.. and many would dump their dreams if they knew they couldnt go cruising without a 65 foot Yacht..
I was lucky enough that I made enough money in the last realestate boom that I could afford the 42..
So at what length and weight does a boat have to be to give you the ability for a safe passage, and still be affordable?
Personally I would think, a performance hull of middle weight of 35 to 38 foot..

[s/v Jedi]

A minimum boat length has been discussed before and there's never consensus on the subject. I think it depends on the areas you want to sail (milk-run or high latitudes too?) and the quality of the crew. I sailed the North Sea on 30' and think we were pretty safe.

cheers,
Nick.

[daddle]

8 knot average. In my dreams. Being a mere mortal, unlike some here, I rarely find enough wind to average more than 4 knots day-in-day-out. And this is with a boat that will pass S/V Jedi in any conditions except motoring. I gotta find some tradewinds...

[s/v Jedi]

Originally Posted by daddle

8 knot average. In my dreams. Being a mere mortal, unlike some here, I rarely find enough wind to average more than 4 knots day-in-day-out. And this is with a boat that will pass S/V Jedi in any conditions except motoring. I gotta find some tradewinds...

So daddle, enlighten us to what type of boat you have!

cheers,
Nick.

[colemj]

Originally Posted by Randyonr3

Actually we went out last week and while we wer screeming up the river under full sail, she was down below baking a cake..

I don't think Dave was making the point about NOT sailing the boat to its potential in good, calm conditions like a river, but rather slowing the boat down when the conditions become uncomfortable at full speed.

Everyone enjoys pushing their boats in calm seas, good wind, sunny days. But picture your boat under full sail in 20kts of wind beating into 5' steep chop ninety degree direction to 12' ground swells. This describes a lot of passage making when slowing the boat down is desirable and most boats your size will not find 8kts of speed in these conditions both doable and comfortable. In fact, yours is a common boat and I have seen many of them in these conditions. They were not enjoying a full speed sail and had slowed their boats down to conform to the conditions. But comfort is a personal thing.

Mark

[Bash]

Originally Posted by estarzinger

We actually studied this question . . . and the answer is . . .

average cruising passage speed (kts) =
2.62 + 0.066*SA/D ratio + 0.051*LWL in feet

We looked at a lot of actual passage times from good sailors/cruisers and this formula comes +-10% most of the time.

I ran the numbers on my boat and came up with 5.88 knot average cruising passage speed. Which would mean that I should average 141 nautical miles a day. That's interesting because for planning purposes I've always used an average passage speed of 6 knots for this boat, which gives me 144 nm days.

estarzinger, have you ever published or blogged anything about the research that led to this formula? I'd love to read more.

[Ram]

I never seem to have enough wind at the right direction (Med) or too much wind in the wrong direction or no wind at all-to get any long runs of speed, sure 4-6 hours at 8-10 knots once in a wile then back down to 4-5 knots- I sailed from Sicly to Greece last year twice -took 4+ full days each time, I think i got 3.2 knots- the wind was about 6-8 knots
I have a personal rule if were moving under 3 knots I start an engine

[daddle]

Originally Posted by s/v Jedi

So daddle, enlighten us to what type of boat you have!

cheers,
Nick.

I just can't resist poking Nick, who is a real asset to the forum...

But his pokey heavy Sundeer 64 ketch might have trouble against this trim Santa Cruz 50 presently cruising in the breeze-starved S China Sea.