Your opinions please!

Discussion in 'Boat Design' started by 8knots, Jan 14, 2004.

  1. 8knots
    Joined: Feb 2002
    Posts: 266
    Likes: 12, Points: 28, Legacy Rep: 352
    Location: Wasilla Alaska

    8knots A little on the slow side

    I was reading an article in PMM over the holidays about a group of trawlers making the trip to the bahama's "The pokie run" In the article is a little map showing the 55nm to the first island. Got me thinking........
    55nm / 7Knots =7.85 hours cruise @5 gph = 39.28 gallons
    OR
    55nm / 16knots =3.43 hours cruise @ 11 gph = 37.81 gallons

    Hmmmmmm I say what could I do with that other 4 hours of the day?
    So here is my little brainstorm. Bear in mind I know little about go fast boats
    but I dug up several PMM articles relating to power cats. after a little reading and scaling out some ads to prove the stuff stated in the article I sharpened the pencil on my trawler profile and went to work. 14 hours later and a few cups of coffee produced this sketch.
    LOA 50.0'
    Max Beam 21.0'
    Max Beam each hull proper 6'6" = beam/length 6.7
    LWL 44'6"
    Draft 3'6"
    powered by twin Cat 3056 @ 188 gross HP
    Tanked for 1,150 gal
    This is all very rough so take it with a grain or too of salt. The articles I read stated that most displacment cats are pushed to S/L's of 3.0-3.75
    I am working on a body plan. I have lots more homework to do. I will post as she develops.
     

    Attached Files:

  2. Willallison
    Joined: Oct 2001
    Posts: 3,590
    Likes: 130, Points: 0, Legacy Rep: 2369
    Location: Australia

    Willallison Senior Member

    I love powercats, so you're on to a winner with me. I've always thought though that they make better coastal cruisers than trans-ocean passagemakers.
    Having said that, more and more are being built to cross oceans and the acceptance of their ability to do so is increasing - PMM is full of ads for fully fledged passagemaker cats. Check out Malcom Tennant's web site ( http://tennantdesign.co.nz/ ) His hullforms are developed as powercats from the start, not simply adapted from sailboat shapes. Or Scott Jutsons stuff for a more stylish approach ( http://www.jutson.com/ )
    There can be little argument that cats can return excellent speed / mileage figures. They also make for a big, square living space. On the downside, the cabins (in hulls) can be pokey, finding a marina berth wide enough can be difficult, and you have to pay fairly careful attention to weight.
     
  3. Willallison
    Joined: Oct 2001
    Posts: 3,590
    Likes: 130, Points: 0, Legacy Rep: 2369
    Location: Australia

    Willallison Senior Member

    After taking another very quick look at your model, I think you may have to narrow each of the hulls significantly. "Displacement", or "displaning" hulls as they are often called, generally have a length / beam ratio of about 14:1. Planing cats would incorporate beamier hulls, but would be inappropriate for 'your kind of boat'.

    Also the bridgedeck clearance looks a little on the low side. I would consider 1 metre to be the minimum necessary on a passagemaking cat to avoid slamming.
     
  4. 8knots
    Joined: Feb 2002
    Posts: 266
    Likes: 12, Points: 28, Legacy Rep: 352
    Location: Wasilla Alaska

    8knots A little on the slow side

    Hey there Will:
    I based the beam of the hulls on one of the articles in PMM. It was in a nutshell about the differance in planing and disp, cats. The article states a average of 6.7 to 1 BL so to confirm I took my scale rule and checked some of the ads in the same issue and it seemed to play out right on the line. the best drawing worked out to 6.5+ to 1. If 14 to 1 be the case then it may be a deal breaker for me.
    44.5'LWL /14=3.17 or about 3'2" eeesh....thats teeny weeny. I have seen some of those super fast ferrys with the Knifelike hulls and wave piercing bows. Really cool to look at but useless hullspaces other than for diesels and tanks. You would have to have Oliveoil arms to service the engines too.
    On the wingdeck issue I agree she is a little low I figured about 24" The underside of the wing is double arc shaped to address to pounding issue. I could raise the deck up another 12" or so, but then goes the rest of the structure. I can allready see docking this thing in a 15KT breeze. Kind of like a big block of styrofoam you could allmost sail it. Twin screws and bow thrusters could handle that tho I guess.
    What do you think of hard chined hulls with the same basic dimensions as shown with say twice the HP say Cat 3406's? and plan on her planing to some extent say 22-24 kts max, cruise at 18ish. Kind of seems like putting a ribbon an a hog to me but we still have room in the hulls for people and stuff.
    Weight would play a big role in the whole thing of course. The intended use of the vessel would be coastal cruising but I would not want to be turned away by 5' swells either.(at reduced speed)
    Aughhhh....So many factors to consider :rolleyes:
    Keep em coming Will 8
     
  5. 8knots
    Joined: Feb 2002
    Posts: 266
    Likes: 12, Points: 28, Legacy Rep: 352
    Location: Wasilla Alaska

    8knots A little on the slow side

  6. trouty

    trouty Guest

    I looked at your line drawing and thought

    I've seen that vessel somewhere...
    [​IMG]
    A Peter Brady design out of Queensland, sprang to mind. And she's already for sale saving you the trouble of building one.
    [​IMG]

    You could read all about her appointments here http://www.boatlocator.com.au/detail.php?mode=10966&p=k

    From memory she might be a little slow at 17 knots IMHO otherwise a very nice vessel.

    Another that might be a bit faster for you along similar lines - this Aerocat...

    [​IMG]

    Of course the price tag might be a little higher to match!.

    Read about here HERE
    http://www.boatlocator.com.au/detail.php?mode=11066&p=k

    Cheers!
     
  7. 8knots
    Joined: Feb 2002
    Posts: 266
    Likes: 12, Points: 28, Legacy Rep: 352
    Location: Wasilla Alaska

    8knots A little on the slow side

    Duh....

    Hey Will:...
    Guess who wrote the arcticle I was looking at... None other than your very own Mr Tennant. I laughed when I dug it back up last night. For those that care It is in PMM December 2003. The article is a brief overview of the diff's in planing vs disp cats. He goes over some of the most basic design issues involved in power-cats. Thanks to Will's posted link I trust his word even more seeing the oodles of actual launches he has under his belt.
    Thanks all

    Trouty...Nice pics, Tho I have yet to make my fortune! :D
     
  8. trouty

    trouty Guest

    Yeah,

    You n me too 8 knots.

    I figure theres no harm lookin - if worst came to the worst, at least I'd know which boat to steal! :rolleyes: :D :p

    Cheers!
     
  9. Willallison
    Joined: Oct 2001
    Posts: 3,590
    Likes: 130, Points: 0, Legacy Rep: 2369
    Location: Australia

    Willallison Senior Member

    The article in PMM I have to say was a great disappointment to me - I've read it 3 ot 4 times in various other mags over the last couple of years - and whilst it's an excellent intro to powercat theory, I tire a little of having to pay for stuff that's appeared elswhere - including Tennants web-site for free!! :mad:
     
  10. Willallison
    Joined: Oct 2001
    Posts: 3,590
    Likes: 130, Points: 0, Legacy Rep: 2369
    Location: Australia

    Willallison Senior Member

    ...sorry - rant is over, now back to the more pleasurable business of your boat 8.. :p

    an extract from one of MT's articles...

    ..on that basis, you could probably get by with a WL beam of around 4.4ft - still pretty narrow to go squeezing accomodations into. But by adding 'knuckles' you could add maybe another 8" giving you a little over 5' - not too bad.....
    The other alternative, as MT suggests is to build a planing cat - but then you will lose a great deal of the economy - it's all wheels and roundabouts as they say...
     
  11. 8knots
    Joined: Feb 2002
    Posts: 266
    Likes: 12, Points: 28, Legacy Rep: 352
    Location: Wasilla Alaska

    8knots A little on the slow side

    I have been studying more Cat designs and I can see the proof of what your refering to.... adding length to get a reasonable L/B ratio. Seems most designers hide this added length with cool looking steps with the stern on each hull extending 4-6' beyond the aft deck. Seems fine to me considering I need to get my wing deck up a little more. I think I need to add some beam overall too.

    You know the added plus to this cat thing in my mind is... What a fantastic charter machine this would make. We have hundreds of Salmon and Halibut charter vessels up here. Most of the 6 packers run Delta's and cruise at about 14-16 kts. They have a hard time keeping there customers from getting sea-sick too. (Gets rough in a hurry up here) If you could run a cat and cruise at say 20-24 kts and "Sell" the fact of a more stable ride,You would own the biz! Most of the tourons want to get there quicker and catch bigger fish. This means you the skipper need to get there first!
    Hmmmmm....... Could be onto the next profession, and you can write it off!
    back to doodling 8
     
  12. trouty

    trouty Guest

    8K.

    Take if from a long time Charter skipper - if you want to own a small charter business - then all you need to do is start out with a really BIG charter business and just take it from there!

    I really don't think theres a LOT of profits to be made in ferrying people out n back for fishing charters.

    As someone in the game - i've taken to "analysing" other "successful charter business" with big new boats etc and EVERY time - i come back to the inescapeable conclusion - they ALL have some other form of income BESIDES chartering.

    For example - a LOT of the Charter boats wetline hereabouts, (catching demersals on long set lines and selling them for fish flesh prices as their basic cash flow).

    Some group of 10 guys comes along and wants a weeks charter and he makes 5 grand and thats a real bonus week - but if he relied upon 10 guys every day of the week to make a living and pay the bills it would never happen.

    They all seem to have that 'additional cashflow deal' with the charter being the creame on the cake...some guys are retired builders who sell the co. for a squillion $ and buy a boat cash - and retire to go 'charter fishing'..

    If the weathers crap they stay home and don't take any bookings - if it's nice and they want to go to sea they do take bookings etc...either way they are over 60 and get the pension anyway whether they work or not!

    To a man I haven't found a charter op whos killin the pig taking people fishing day in and day out....just doesn't seem to work that way..

    Best I can tell - you have to have some other form of income. The boats have to meet some pretty stringent survey requirements, and after 5 or 10 years often the survey authority inspectors will suggest you "retire" the vessel (sell it into the recreational boating market) before they "fail it's next hull survey".

    These surveyors like to keep a well presented modern up to date fleet for tourists - and old run down boats don't suit that image.

    If you figure that rate of depreciation on a vessel into any charter vessel operation - well - in order to be able to replace the vessel at say 5 or 10 years - you'd need to charge so much for each days fishing - no one could afford to come...

    Really speaking the Charter industry seems to be dominated by either well heeled corporate types who can afford to own such a expensive depreciating assett as a tax write off and employ a skipper to run it so he can fish when he wants.

    The other type charter op is the guy who - has a wetline license or lobster license etc and fishes to pay the fuel bills, slip fees and maintenance costs and takes the odd charter when they show up for a little profit taking...

    I can't seem to find anyone in between who actually leases a great big new boat and takes clients fishing every day - always booked etc etc and actually stays in bidness - I see plenty try it, but few succeed.

    Theres always someone who enters the industry with a big wad of cash from an inheritance - lottery win or whatever - who thinks they will play merry hell with a big stick n break things as far as setting the world of charter fishing on fire. Usually they go out with as big a bang as they make on the way in...often in the frst 12 months.

    Sadly the reality of charter fishing as opposed to the "anglers dream of retiring to charter fish" are just that, pipe dreams...

    The odd guy in places with LOTS of high roller tourists might do it for a few years with a leased boat etc etc and seem to be successful (if you believe their own press they are writing) BUT the reality is, these types who try it are just digging a deeper hole- bigger boats, bigger leases - less profits and the higher their debt servicing.

    About one of the ONLY "semi profitable" operations I've seen is a pair of sailing cats in the 60 ft range who do twilight cruises up our west coast in protected waters - showing tourists from a resort the dolphins manatees etc and trolling a lure from the transom for a big mackeral - while BBQing a few mackeral steaks and handing around a glass of wine etc to the 60 or so passengers who all go out for a short 1.5 - 2 hour twilight cruise...

    Now these guys have incredibly low fuel costs - it's more of a cruise than a bonafide fishing charter...and it's whats called high volume, low value - tourism...60 passengers all paying $50 a head for two hours work with no fuel bill..

    The resort spends all the $ to attract the tourists - he has a captive market with high disposable income (theres bugger all elses to do except swim with the dolphins and sunbathe) and seems to do very nicely thank you very much...

    This sems to be a LOT different to the charter fishing industry which is a cutthroat bloody game.

    Hope I'm not dashing anyones illusions here - just a bit of a realists look at the charter fishing game...

    Most keen angkers idea of chartering is that wealthy clients pay you to go and fish fr them because they are to busy to do it for themselves. The reality id you seldom ever get to fish - you drive the boat and maintain it - you find the fish - rig the lines - gaff the fish and release (or fillet it) - you untangle their lines, fix broken tackle, basically everything but actually fish.

    Ohh yeah - you also get to hose down their spew when they are sea sick - could be anywhere down in the berths - in the galley or lounge - etc...or if your lucky it's up on deck where you can just hose it out the scuppers...

    Nearly all charter skippers I know last about 10 years max before they have had it up to the back teeth with dealing with people all the time, having to put on a happy smiling face even when they don't feel like it..

    Theres a lot to chartering that never gets mentioned in the anglers dream retirement novel...coz it was written by a frustrated angler not a burnt out charter skipper...

    The last alternative income for a charter skipper is 'bank robbing', a fast motorbike - sawn off shotgun and Balaclava is all you need...jus make sure ya life insurance is paid up before you start. ;o)

    Cheers!
     
  13. Unregistered

    Unregistered Guest

    Hi,
    I'm thinking of starting a charter business, does anyone have any useful suggestions?

    :)

    Only joking!
    Trouty, that was a very interesting post. I have often thought that there are lots of areas of the marine and related industries that are not as profitable as they seem.

    Tom
     
  14. trouty

    trouty Guest

    Hi Tom,

    I was only talking to a naval architect theother day about the Charter Industry- he gets to ride on most of thenew boats he designs once they are put into survey and start work - invariably the new owner will invite him along gratis for a weeks fishing in the first few months operations to llok at how the new vessel is performing etc.

    He says to me repeatedly, that it beggars his belief that these guys will ever make enough $ to justify the capital expenditure outlay on a large new charter vessel, they may get a lot of bookings initially while the vessels new and so on, but eventually - there wll be a newer bigger better boat enter that area and marketshare is lost - the boats depreciated and they sure aren't making enough profits in that first year or two to make up for the depreciation rate on the vessel in subsequent years once repowering etc comes into the equation..

    About the only industry I know of where they DO make serious enough $ incomes to maintain a relatively modern new fleet is the lobster industry where a new state of the art boat every 5 - 10 years is the norm..

    No for charter work - they must have some other form of income for periods when there is no charter bookings and usually it's some form of long line or fish trap type endorsement...that pays the fuel - and maintenance and allows them to actually explore and FIND the productive coral lumps to mark of their GPS's to take charter clients back to when they do get bookings.

    It's an easey game to start in, but a tough game to last in without some ofther income string to your fiddle.

    Cheers!
     

  15. 8knots
    Joined: Feb 2002
    Posts: 266
    Likes: 12, Points: 28, Legacy Rep: 352
    Location: Wasilla Alaska

    8knots A little on the slow side

    Yes Trouty your right for the most part! I do thank you for the time you took to post. I'm not saying I would start tomorrow but we have a very specialized (high priced) market here in Alaska. Also a very short Cattle boat season 1st of June-second week of September so say about 14 weeks of "working days" You are right on about having another job or income! We have the same Big resorts and Cruise ships dragging people in by the zillion on there dime. Usually dropping them in small towns with not much to do, most of the time you can "do the town" in a few hours. I will use the town of Seward as a model. here is what they have for a charter fleet
    roughly 8 BIG 150 passenger "sightseeing/wildlife viewing" vessels
    giving 2 hr 4hr and 8 hr cruise options ranging from $50-130 a head
    roughly 4 mid size 70'ers that are licensed for 16-20 "fishing" passengers
    average $150-180 a head
    roughly 36 small 6 pack boats(licenced for 6 passengers + crew) Not sure if they call it that in OZ? These range from 18' alum jet boats to 50' sportfisher types. $150-200 a head
    A skipper with a 6 pack can expect $200 for the day + tips(4-6hrs)
    1 deckhand say $50 + tips (fish processing) @ 20ish from each passenger
    but he gets to clean and maintain the vessel so he's got an 8 hour day
    If you manage one of your clients yarding in a 300# halibut "the boat gets a nice tip Iv'e heard of $500 before. more realistic would be all the passengers rustling up $150-200
    In the season most guys can limit out in a few hours. This depends mostly on a competant skipper and a fast boat! "To the victor go's the spoils"

    So in a nutshell It would be nice to work 4 months of the year and spend the rest making millions designing boats :D :D :D
    So when are ya movin? :p
    8
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.