Ocean crossing in a 25' cruiser

[Portofino]

Welcome to the Forums.

It will not work diesel powered unless you intend to drift most of the way.

If you really are thinking of crossing the oceans, then throw away the diesel engine and gearbox, replace with a marine electric engine. Make up the weight of the removed diesel engine minus the electric engine using Leisure / Deep-cycle batteries.

Dispose of the diesel tanks, make weight using deep-cycle Leisure batteries to the weight of the tank(s) and diesel contents. Keep all weight low down

Fit solar panels and controller.

This is possibly the only way you will do it with the boat specified .

If you do not reply to this then I assume you have gone back to live under a bridge somewhere in Finland, Norway or Sweden?



.

All outside the "brief" time is important -about a week or so ,people can sail or row thousands have ! but it takes ages .
Unless your design can do 20+ knots ( at night+ cloudy daytime.)

 

[alant]

All outside the "brief" time is important -about a week or so ,people can sail or row thousands have ! but it takes ages .
Unless your design can do 20+ knots ( at night+ cloudy daytime.)

Probably borrowing this http://www.solarnavigator.net/history/cable_and_wireless.htm

 

[prv]

You will find that UK harbour masters and CG have a few powers which prevent unsafe boats from going to sea.

Really? News to me. Unless you're talking about port state inspections etc as applied to cargo ships. But they generally don't seem to apply this regime to amateur vessels.

Many years ago a friend of mine pulled an old RIB out from under a bush and tried to go to sea in it sans flares, radio, lifejackets etc and with an unreliable engine and no experience of motorboats. The chosen launch site was by a Coastguard station, and they came and had a word - from the senior guy's manner I think if he had had a right to prevent the boat launching he'd have exercised it. But what he carefully said was "I am formally advising you not to launch."

(My mate took the advice, went and bought at least some lifejackets, and launched at a more sheltered location to get used to the boat.)

Pete

 

[Dave99]

The reason you need a big boat with a big range for this is cos it takes a lot of fuel. Fuel is heavy. Don't think you would get life insurance for this one. What would the boat stability curve look like for starters?!

 

[Dave99]

One other thing - how do you plan on doing 25 knots in 3m seas with big swells and waves breaking over the boat - you would be lucky to get 6 knots. Trust me I have crossed the atlantic quite a few times in boats up to 60m.

 

[Searush]

At displacement speed it all starts to sound a lot like Half-Safe to me - the amphibious jeep in which a crazy Aussie and his wife crossed the Atlantic in the 50s. They had to make about half a dozen attempts before they actually got going properly and made the crossing - I think for the successful attempt they were towing a floating fuel tank behind them. Seem to remember something about them needing to take on extra fuel from a ship they happened to meet - presumably had they not been lucky enough to encounter it, they would have run out of fuel mid-ocean and died of dehydration and starvation...

Pete

Quite so, he also had a tank built to sit underneath the jeep that was jettisoned when empty. And yes, I remember them stopping a passing freighter to beg a few cans of fuel too. Great book if you can find a copy "Half Safe" by Ben Carlin.

 

[Gushter]

The idea is becoming more plausible, though still not fully sensible. Responding to a couple of ideas on the forum, I agree a bigger boat may be better. Gasoline is out of the question, for safety reasons and for the torque need. Further, the expected trip distance is around 2,200 nm (Azores to the Caribbean or Cape Verde to the Caribbean) which simplifies the requirement. Assuming we average 18 knots (12-15 at first, rising to 22-24 knots as the fuel is expended), this is just 5 days straight motoring. Say it is 7-8 days if we let the poor engine rest or lower the speed. Weather permitting we could even change the prop half way, after we drop the tank, to match the load (that would be fun at sea).

Latest thought is to spread the fuel requirement between the boat and a tow tank. May be we put around 700 gallons extra in the boat and we tow a torpedo like tank with a capacity of around 600 gallons. We have to work out a safe way to refuel at sea... we'll think about that. This way the boat will be overloaded only 20-25% internally with a range of around 1,200 nm if we need to drop the external tank at some point.

Regarding the back up outboard diesel engine, it is not so much to get home at hull speed (not possible, I agree) but to have power to keep the boat in the right direction vs. the waves until help comes or we fix the main engine. Further, we would definitely load the boat with water instead of diesel (adjusting for specific weight) and do some testing in various conditions.

Regarding rough weather which most of you seem to be worried about, this is supposed to be a one-time attempt, in favourable weather. We'll have sat phones and get up do date forecasts. If the weather starts getting worse, we will adjust, even turn back. There will be a team on land doing the weather routing for us. There is still a risk but this is not a walk in the park as most of you have pointed out.

Next: pick the boat and read up on diesel engine repair at sea. Still planning to go for the "Darwin award of the year."

Regards,
Gushter

 

[alant]

The idea is becoming more plausible, though still not fully sensible. Responding to a couple of ideas on the forum, I agree a bigger boat may be better. Gasoline is out of the question, for safety reasons and for the torque need. Further, the expected trip distance is around 2,200 nm (Azores to the Caribbean or Cape Verde to the Caribbean) which simplifies the requirement. Assuming we average 18 knots (12-15 at first, rising to 22-24 knots as the fuel is expended), this is just 5 days straight motoring. Say it is 7-8 days if we let the poor engine rest or lower the speed. Weather permitting we could even change the prop half way, after we drop the tank, to match the load (that would be fun at sea).

Latest thought is to spread the fuel requirement between the boat and a tow tank. May be we put around 700 gallons extra in the boat and we tow a torpedo like tank with a capacity of around 600 gallons. We have to work out a safe way to refuel at sea... we'll think about that. This way the boat will be overloaded only 20-25% internally with a range of around 1,200 nm if we need to drop the external tank at some point.

Regarding the back up outboard diesel engine, it is not so much to get home at hull speed (not possible, I agree) but to have power to keep the boat in the right direction vs. the waves until help comes or we fix the main engine. Further, we would definitely load the boat with water instead of diesel (adjusting for specific weight) and do some testing in various conditions.

Regarding rough weather which most of you seem to be worried about, this is supposed to be a one-time attempt, in favourable weather. We'll have sat phones and get up do date forecasts. If the weather starts getting worse, we will adjust, even turn back. There will be a team on land doing the weather routing for us. There is still a risk but this is not a walk in the park as most of you have pointed out.

Next: pick the boat and read up on diesel engine repair at sea. Still planning to go for the "Darwin award of the year."

Regards,
Gushter

Its the Atlantic.
So pls define "favourable weather", for a trip all the way across.
Also, at which point, should the forecast be below whatever limits you set, would you "turn back"?
Having, like many on here, done transatlantics, in small boats, with all of us hoping to cross in "favourable weather", so would be interesting to know, what limits you envisage experiencing.

 

[fergie_mac66]

Dears,



The basics, we can take care of: single diesel for efficiency, 2nd small outboard for backup, other safety, dry food, shake in of the boat, etc. We believe we can handle slamming the waves for a week but we will do our best to choose a good weather window, say January 2014 from the Azores and we plan to complete the crossing in 8-10 days.

Now, the tough question: We expect to make 2.5 nmpg @ 20 knots (the boat can do in excess of 35 knots) but if there are significant waves, it would be less. On the other hand, there is always the option to drop to hull speed and extend the voyage, food permitting. Still, we estimate we need around 1,200

Thank you,
Gushter

January ? in the atlantic

 

[Gushter]

Alright, January may not be the best month in the North but looking at the Cape Verde to the Caribbean route for the last month and a half:

Last forty five days, hourly data for buoy 41041 (14N, 46W):

90% of the time, wave height was below 2.4 m, never exceeded 3.5m; median was 2m
90% of the time, wave period was above 5s, peaking around 7-9s; median was 7 sec.
40% of the time, wave steepness was average, 55% of time was steep but never very steep

Come on guys, I have been in the high seas as well. 2m waves with long periods, and wind at the back is not so bad. This is 90% of the time! Even if we have to reduce speed for a few hours to wait for the waves to calm down, we would still make the average speed. It will be uncomfortable but this is a one time deal as I said.

Gushter

Wave period

 

[Chris_d]

Doesn't a Jeaneau 805 run an old KAD44, will need the valves doing before you get across

No Volvo leisure engine will run at cruising speed for 240hours without some attention!

 

[oceanfroggie]

Impossible due to limited fuel range even if you installed additional tanks. Wrong vessel type, wrong route, wrong time of year.

 

[Sundowner Portofino]

Surely this is a joke thread - but just in case it is not - I think the OP needs his / her head examined

 

[TimBennet]

Impossible due to limited fuel range even if you installed additional tanks. Wrong vessel type, wrong route, wrong time of year.

Yes, if the OP had done even the slightest background reading on achieving this, he would have seen in Beebe's 'Voyaging Under Power' a discussion of the various transatlantic routes from someone that had been there, and done that. The ideal route is via the Azores and Bermuda when it's a flat calm under the Azores high. Sailing boats cross in winter via the Canaries because they need the trade winds to make progress, and put up with the squalls and constant rolling as a necessary evil.

 

[Nick_H]

I think you'd need a support vessel to bunker fuel. This could leave the Azores a few days before you to be mid passage at the same time as you. This means you only need a fuel range of 1100 miles plus contingency. You could minimise the contingency by fitting fuel monitoring to the boat so you could analyse your fuel burn in real time, and if you start to get ahead of the curve in terms of fuel usage you could drop to hull speed for a period to get back on track.

Alternatively, if the voyage is well planned, organised and promoted, and you could get substantial sponsorship, then you may be able to persuade a company operating cross channel vessels to rendezvous with you to take on fuel. To be honest though, if you were considering setting off into the Atlantic with a 50% overloaded boat, you're unlikely to convince anyone that you're well planned and organised.

 

[sarabande]

"Gasoline is out of the question, for safety reasons and for the torque need. "


You really don't know what you are talking about. The engine fuel type is not necessarily the determinant of torque, and I have no idea why you need to consider torque. It's all about putting thrust out of the prop. The choice of diesel is made on a multiplicity of other factors including energy density.

Typically... (per gallon (US)

Petrol 131.9 MJ
Diesel 146.3 MJ
Biodiesel 133.1 MJ


I cannot see why any sponsor with only one foot in the real world would wish to support anyone with such a clear deathwish.

 

[Gushter]

Thank you guys, your feedback is appreciated. I've heard about the book mentioned and already ordered it. I was alternating between the Canaries or the Azores route and I am aware of the Azores High, so will heed the advice (originally this started as a sailing trip). So the route and the timing we can fix. My worry regarding the Azores was the Gibraltar to Azores trip but will read up and then select the best option. It does not have to be done in one trip, i.e. we can go to the Azores then fly back home and do the Bermuda trip on the next vacation. We can take 2-3 weeks of work at a time but being gone for 2-3 months is out of the question.

The point about the engine reliability is very valid and we may have to rebuild the engine and extensively test it to maximize the reliability. I still believe it can be done either with overloading the boat or towing a tank. So the key outstanding points are 1) proof of concept (boat speed, propeller options and consumption either planned overload); 2) engine reliability and options to repair at sea (what are the most likely faults); 3) boat selection; 4) head examination of the OP.

Would you recommend an alternative planing boat then? Just be easy on the price.

Thank you and best regards,
Gushter

 

[Portofino]

Ok I,ll toss in 2 pennys worth
Assuming a " can do attitude "
10-12 days or shorter needs to be a planner ,but has to carry the fuel as well -look at this -note the narrow beam+ very deep V for sea keeping at arround 20-25 knots or what ever

http://www.yachtworld.com/core/list...nits=Feet&access=Public&listing_id=76712&url=

Hang on I have not finished -remove the petrols and fit a lowdown torquey diesel like the D6 ( none supercharged 310 variant) .
Ordinarily this would rocket to 40+ knots but you don,t want this -You need to re-gear/ reprop it so the massive torque curve hit a sweet spot at 20-25 knot -so it can lft up and plane with the extra wieght ( displacement of the fuel)
Down below loads of room to fit fuel bladders evenly distributed + food +water etc
Power/ torque of the " new" engines + fuel efficiency of the sterndrives ( correctly propped) in this hull
You might have a theorectical chance of blatting across arround 25 knots ish? In the time window you have set

Bit of maths 2200 miles @ ave 22 knots = 100 hrs
@65 lt /hr = 6500 L X .84 Kg ( wieght of a L ) = 5400kgs
So find a planner that can carry this - I recon 40fter + as allready suggested .
Remember this is av speed over the whole trip 100 hrs -= 4.16 days Do able in calm conditions all you need is 5 day window

Displacement -well that's easy @ 4-6knots .
Towing a torpeedo will not work ,boat will not plane

 

[TQA]

Google Dashew and WINDHORSE

That is what you need.

 

[Divemaster1]

Bit of maths 2200 miles @ ave 22 knots = 100 hrs
@65 lt /hr = 6500 L X .84 Kg ( wieght of a L ) = 5400kgs
So find a planner that can carry this - I recon 40fter + as allready suggested .
...................

Not many 40 footers that can do that speed with less than 300 hp (fuel consumption) ..... actually none that I know of... particularly not with the added weight of approx 6 T (weight of fuel and tankage)... Displacement speed is only realistic option ...... or go much bigger .... Remember Virgin Challenger (70 foot and topical these days)..... averaging about 37 knots, but believe she had to re-fuel underway.....