Power Cat or Sailing Cat?

[SteveSadler]

Cats can be very fuel efficient at certain speeds. Foil assist cats are designed for 20kts +
to get the wetted surface dry. For a cruising boat going 2k miles, the slower you go the better fuel mileage you'll get. Cats are great powerboats, no roll, less pitch, but you don't need 300hp to cross oceans. Thats for more speed than is fuel efficient. I ran a 56' cat with 85hp engines and it would go 15kts! why anyone would put more hps in it is beyond me. My suggestion is buy a sailing cat and don't use the sails. Take the rig off! Unless you want 20kts, you don't need the extra hp, expense, maintenance. Most cats will do 10 or 12kts under power alone.

[Sailmonkey]

Originally Posted by belizesailor

Never seen one. Do you know of any foiling cruising power cats?

None I’m aware of that are not a garage project.

[Chotu]

Originally Posted by Kenomac

A true powercat is much different than a sailing cat converted to a power only cat. The hull design is completely different with the true powercat designed for optimum speed and some lift.

Exactly. Which is why I was asking about foil assist.

Lift can be created by little foils to lift a displacement hull in the same spots a flat bottom power boat would have lift. Not having a flat bottom also results in a smoother ride in chop.

This is where my thoughts about adding some foiling come from.

[Chotu]

Originally Posted by SteveSadler

Cats can be very fuel efficient at certain speeds. Foil assist cats are designed for 20kts +
to get the wetted surface dry. For a cruising boat going 2k miles, the slower you go the better fuel mileage you'll get. Cats are great powerboats, no roll, less pitch, but you don't need 300hp to cross oceans. Thats for more speed than is fuel efficient. I ran a 56' cat with 85hp engines and it would go 15kts! why anyone would put more hps in it is beyond me. My suggestion is buy a sailing cat and don't use the sails. Take the rig off! Unless you want 20kts, you don't need the extra hp, expense, maintenance. Most cats will do 10 or 12kts under power alone.

True as well.

I am getting 8 knots off a single 30hp engine now on a 49ft boat and have 400 mile range with 150 gallons.

I only run one engine at a time for maximum efficiency

Trying to see where to go from here.

Ideally I want to go faster. I'm under propped so I'm hitting max RPMs on the engine at 8 knots.

Problem is I'm a lifelong sailor.

No clue about how to set up a great power boat.

[SteveSadler]

Chotu brings up a good point. Fuel consumption. Even at 3miles per gallon, better than Chotus current milage, my last passage from Aruba to Tahiti, about 6000 miles would have taken 2000 gallons at $3.65 or $7300. The longest passage, 3000 miles would need 1000 gallons +to store somewhere.
8 knots would give a nice 15 day passage, but not much better than our 17 day passage burning no fuel.
Of course most power yachts budget for this expense, and most are in a different income bracket than than cruising sailors.

[Chotu]

Originally Posted by SteveSadler

Chotu brings up a good point. Fuel consumption. Even at 3miles per gallon, better than Chotus current milage, my last passage from Aruba to Tahiti, about 6000 miles would have taken 2000 gallons at $3.65 or $7300. The longest passage, 3000 miles would need 1000 gallons +to store somewhere.
8 knots would give a nice 15 day passage, but not much better than our 17 day passage burning no fuel.
Of course most power yachts budget for this expense, and most are in a different income bracket than than cruising sailors.

Right, but... I have a $60,000+ rig to pay for in order to enjoy free rides.

I think I need to move up an income bracket to be able to afford the rig. Hahaha

That's why I'm going down this intellectual path.

If there was already a rig (and sheets and wincjes and sails) I wouldn't even be thinking about this.

[belizesailor]

Originally Posted by Kenomac

I’m not sure what size boat the OP is looking to buy, but sails for a 54ft Cutter cost over $25k, and a rigging replacement $15k.... which can also buy lots of fuel

But in contrast, the rebuild/replace cost on larger diesels is pretty horrendous.

[belizesailor]

A compromise option for a sailor considering a power cat would be a power cat with a real nice sailing dinghy...power to the next anchorage then go for a day sail!

On a good sized power cat you could easily carry a fully rigged Laser or 2. [emoji41]

[hyamsbeach]

I’m having similar thoughts about crossing back over to power.

I originally had a Lagoon 38 for seven years then bought a Beneteau Fly 30 for eighteen months.

While I cruised economically at 18knts using 45-50 litres per hour I found the trips rather uncomfortable up on the plane.

I recently sold the mono and have been looking at sail cats but they are now fairly expensive here in Australia compared to power cats.

While I love the sound of the wind and waves I like the advantages of rapid retreats when the elements turn against me.

I considering a 4.5 ton 2008 Schionning power cat with twin 100 bps and expect it to achieve a cruising speed of 16-18 knots @ about 35 litres/h

I will use it in Jervis Bay and trips up and down the coast with the biannual 2000 mile trip return to the Barrier Reef.

What should I do?

[DefinitelyMe]

Google 'ieta catamaran'. We met the owner/builder two hears ago in the Marquesas Islands. According to him both the build costs and running costs are lower than a sailing cat. By quite a margin in fact. Having seen the boat I believe him. Masts and rigging are expensive, but also the reinforcing structures for that mast and rigging. Either way you have to pay for engines and all the periphery to them.

However, ieta is a $1.5M boat. If you can afford to be in that category I think q motor cat could just end up being both more convenient and less expensive. If you can't afford to be in that category then sail starts to be much more economical. The question then becomes, are you willing to pay a bit extra for the convenience of not having to deal with sails? If I could afford it I would be.

[Chotu]

Originally Posted by DefinitelyMe

Google 'ieta catamaran'. We met the owner/builder two hears ago in the Marquesas Islands. According to him both the build costs and running costs are lower than a sailing cat. By quite a margin in fact. Having seen the boat I believe him. Masts and rigging are expensive, but also the reinforcing structures for that mast and rigging. Either way you have to pay for engines and all the periphery to them.

However, ieta is a $1.5M boat. If you can afford to be in that category I think q motor cat could just end up being both more convenient and less expensive. If you can't afford to be in that category then sail starts to be much more economical. The question then becomes, are you willing to pay a bit extra for the convenience of not having to deal with sails? If I could afford it I would be.

The. Thing is.... Engines are way cheaper than a rig for my boat. Plus I already have them.

So basically it costs me $60,000 to sail or $0 to be a trawler type power cat.

Worst case scenario I spend $30K on brand new engines since I am running twin 30hp currently.

But I can also sell these 30hp engines if I want to go up in power, offsetting the cost of the upgrade.

I feel a lot of people talking about how cheap sailing is have never bought a complete rig before. It's way WAY more money to buy a mast, boom, forward beam/seagull striker, winches, lines, traveler, sails, furlers, etc.. than engines are for the same boat.

Thanks for the name of the boat to Google. Checking it out

[CatNewBee]

Even sailing most of the time in the Med I spent last year about 1.000€ on fuel, and most of the time I have used only one of the engines motorsailing at low rpm and only if absolutely necessary. If I had used both engines all the time at 80% power as advised insted sailing, my fuel costs would have been 8-10 times higher.

Without sails cruising would be very expensive and one need to stop over at marinas frequently for fuel.

It is OK, if you just go around the corner for fishing and anchoring out, but not so good on long passages and travelling around the world full time.

[Chotu]

Originally Posted by CatNewBee

Even sailing most of the time in the Med I spent last year about 1.000€ on fuel, and most of the time I have used only one of the engines motorsailing at low rpm and only if absolutely necessary. If I had used both engines all the time at 80% power as advised insted sailing, my fuel costs would have been 8-10 times higher.

Without sails cruising would be very expensive and one need to stop over at marinas frequently for fuel.

It is OK, if you just go around the corner for fishing and anchoring out, but not so good on long passages and travelling around the world full time.

I'm getting 2/3 of a nautical mile per dollar spent in fuel, assuming $4.00/gal. Sorry about all the imperial numbers.

My boat is not at all currently optimized for power boating. It's under propped.

Assuming the Euro and dollar are equal ( to do a rough comparison), for your 1000 Euros, I can travel 666 miles in my poorly set up power cat currently.

For 60,000 euros (the cost of mast, boom and sails only), I can travel 40,000 miles or... 65,000 kilometers.

Using Wikipedia, a circumnavigation is definited as follows:
"Yacht racing therefore defines a world circumnavigation to be a passage of at least 21,600 nautical miles (40,000 km) "

So, I can theoretically do approximately 2 circumnavigations for the same price as a rig.

How many circumnavigations does the average rig do before people start re rigging? Needing new sails? New halyards and sheets?

Spending $60k on a rig sure doesn't seem like the less expensive way to go.

Sure it's the fun way, the quiet way, the pleasing way and the boat would be faster. But not the cheaper way.

My intended use is USA coastal, changing with the seasons, Caribbean and Europe. Maybe farther if it seems fun.

More from Google:

"The minimum distance between New York City and London, UK is 3290 nautical miles, on a great circle route from the fairway buoy to the entrance to the English Channel. If you were so lucky to make a speed made good of 8 knots, it would take you just over 17 days"

2/3 of a mile per dollar means it costs me $4,385 to go from New York to London.

That's about the cost of new wire stays or a single sail on a boat this size.

[Chotu]

The above post also would require me to carry 1,233 gallons of fuel, completely eliminating my 2/3 of a mile per dollar figure.

So probably it's not possible to do this in my boat, which is why sails are better for crossing oceans.

If there were sufficient refueling stops (Labrador, Iceland, etc) maybe it could be done. But no way returning to the Americas by the southern trades route.

All that math and logical just went around in a circle!

Ugh

[Chotu]

So for coastal cruising, the Caribbean and shipping the boat across oceans, power cat is good. For traveling around the world on its own, sails are the only choice for this boat, given the efficiency is due to its light weight and small wetted surface area.