plate boat design

[myusernam]

Why are the majority of plate boats aimed at the offshore market short, fat and shallow v'd?
They don't resemble their fibreglass competition.
Fair enough it's lighter just put some bigger tanks in (a bonus) or a ballast tank, or make it a bit narrower.
For example a mate has a 5.3m aluminium boat. It's a massive thing requiring tabs because it is so high sided and it requires 150hp. It's only 5.3 m long so it rides poorly in nq chop, is quite wide, high volume plus it has a 16 degree v.\Now this would be a great allround NT boat, or gulf boat. But in Townsville where it is built, the creeks are small and it is too big for the creeks. But take it offshore and it is still a 5.3m boat with a 16degree v. Why can't plate boats more resemble what we know works from fibreglass builds?

[scottar]

Why can't plate boats more resemble what we know works from fibreglass builds?

They can and from some builders they are. Why aren't more like it - plenty of possibles. Economic pressure, the "boat builder" may be little more than a welder or be working with a poor designer, the requests of clients, the additional outlay in equipment/man hours to try and get alloy to form to the compound curves that glass will are possibly just a few

[robothefisho]

I'm pretty sure you just described what most of the wanna be plate boats are... the proper heavy duty boats are nothing like what you describe. For one they are heavier than an equivalent length main stream glass boat. Some of the smaller ones are reasonably shallow v, 17 or so degrees because they are a bit top heavy having self draining floors and high sides. They need higher sides because of their floors being 200mm or so higher.They should ride just as well as their glass equivalent, but in my opinion are less stable. A lot of glass boats have planing planks and more strakes also making them easier to power.

[DaveR]

They might market some of the smaller, shallow V platies as offshore boats, but they are more of a bay boat than anything. But as long as they have high sides, self draining decks and water ballast systems, they will continue to be marketed as offshore rigs. Much like Mazda advertising their family cars as "zoom zoom" sports cars. If you knew anything about cars you'd take it for what it is, stupid marketing. Same with hulls, always do your research on hull design before buying something for a specific purpose like offshore work. There are some very nice platies out there, some not so nice.

[Noelm]

Which do you consider some of the nicer ones?

[Chris Tucker]

Wouldn't worry about it to much guys he's just trying to bait me. Here is your one nibble, I won't be back to this thread after this...

The market trend (driven by the majority of plate boat clients) is for deeper and deeper dead rise and more offshore capable boats. This is evidenced by the fact that the first question asked on forums or facebook every time a new boat is launched by any of the builders is "what is the deadrise?". The Australian power boat market is dominated but small low dead rise, low sided aluminium tinnies and plate boat builders will never be able to compete with them on price. So instead they try to tap into the alternate perception that plate boats are a tough go anywhere product by producing boats that have the capability of going anywhere. It is an interesting market trend which I can look at from a safe distance as I'm involved in both side of the pleasure boat industry is that Aluminium Boats are getting heavier and glass boats are getting lighter. I had a boat repair guy a couple of weeks ago comment that after he pull the front runner of the inside of the hull in to V'berth area that the glass was so thin you could see shadows through it. Plate boats are getting heavier because clients a demanding a stronger wore rugged product and going with thicker plate makes getting a good finish easier (thus saving money) while glass boats are getting lighter because it make them cheaper to build and means people can get a bigger boat behind their chosen tow vehicle.

The brand you're talking about, Hammerhead Boats, has 4 (plus one at drawing stage) distinct product lines, not including their custom boats built to survey. So like anything it is a case of picking the right product for your desired use.

1. Sandfly. Rugged "V" nosed punts which depending on size have a dead rise around 4 degrees. Like any punt of their type these are ideally suited to dead flat (shallow) water.
2. Firefly. Originally conceived as river boats they are wide and stable with low gunwales that are wide enough to walk on and large raised casting deck. These boats have a low deadrise of around 11-12 degrees (depending on the size) and large reversed chines forward making for a super dry t'shirt and shorts ride and superior stability at rest. Despite being a creek boat these have been seen heading out to the reef (which I'm sure our anonymous posted will consider a design failure).
3. March fly. These were originally Hammerhead's "entry level" plate boat range. The styling is a bit simpler and the option list slightly smaller. They are good honest boats all with a deadrise of at least 16 degrees and depending on the client's requirements can be equipped with everything from kill tanks to under gunwale rod lockers. Due to client demand this range has recently been increased to 5.1m (because people wanted to go further offshore).
4. Dragon fly. With deadrises going as high as 25 degrees as the boats get bigger, stepped hulls from 6.1m, full hard tops from 5.8m The Hammerhead Dragonfly range would be one of the most advanced production plate boat ranges in the country. Yes, the boats are too big for fishing in your average creek or river, but that's not what the owner's buy them for. The next two 5.3m dragon flies (rolling out of the factory this weekend) have more deadrise and a finer bow than your "mates" boat, because this is what the market has asked for.
5. Finally the mystery range. Might just be your cup of tea, you never know, but until Gerard is ready to launch it you'll just have to keep tilting at windmills.

The biggest advantage of plate boats is that you're not stuck with a mould you've invested thousands in so in the rare cases where performance hasn't be quite what we were after or where we've received genuine critical feedback we have tweaked the design to remove the issues. A classic example of this is the Firefly you were criticising in the thread the other day. The early boats were riding on their chines rather than the hull, this gave them an incredibly soft ride and it cornered like it was on rails, however, it was important to get engine trim just right. Once we worked out what was happening we modified the chine profile which means the boat now rides a little more like a "normal" boat with a 12 degrees deadrise but is far easier to drive.

[robothefisho]

Chris,
I for one love the fact you comment in detail on Ausfish. Genuinely interesting and informative reading that is otherwise not accessible to the average mug.

[DaveR]

Which do you consider some of the nicer ones?

Stuff I can't afford like semi-custom rigs (from builders like Moda and others). Metal Shark if I was in North America. On a budget and of those with reasonably wide dealer networks, I consider mid-large models from Surtees and Bar Crusher (maybe I will cop a hiding for mentioning them) the benchmark over some of the more mainstream plate entries from Quintrex/Stacer and the like, which tend to have less comprehensive stringer designs (may not necessarily impair them too much, but others go the extra mile).

[lembo]

I find it funny how your questioning the builder. id be questioning the buyer. buy a shallow v 5.3 platey its going to perform like a 5.3 platey. buy a deep v offshore designed fibreglass hull its going to perform like one. i don't expect my boats to perform like anything there not. just because its built in Townsville don't expect it to perform well in all waters Townsville have. hammer head build awesome offshore boats, creek boats, semi smooth water boats there work and designs are tops. just buy one that's fit for purpose . if you want a heavy deep v boat go buy one theres plenty around, don't buy a shallow v platey and expect it to be an offshore weapon.

[myusernam]

thanks chris for you reply. I wasn't trying to bait you, i have asked this question previously , long before you were on here.. And I genuinely want to know the answer. But I was hoping you would reply, mainly because I think you are qualified to answer.
,
I specifically didnt mention hammerhead. I am referring to all plate boats built in australia. Although my mates boat is a 5.3 dragonfly (genuine mate been out in it etc) Its no big deal that it's not my choice of boat. boats are a very individual thing. It's very well made. And as a semi custom, you can ask for it to have whatever you want

All the plate boats I have seen, with possibly the exception of noble super v,s, seem to have moderate v's. Not that deadrise is the be all and end all. I daresay 24 or 25 deg is too much. Formulas might ride nice in a straight line but the rock around at rest. But I dont think there is a sub 6m plate boat advertised on the net with more than a moderate v. And yet you can get glass hulls (lets see hooker, cyclone (same now i guess) haines, bertram, wahoo, seafarer etc in sub 6m lengths with 19degree or higher v's. I think my 15' haines is over 20.. Im not having a personal go chris, im sure you can design whatever the customer asks for. I'm asking why. And even the 6-7 m range (and I think plate boats have the edge in that you can go over 7m and still be trailerable if you have the money) they still dont seem to be very deep v's, with the exception of perhaps fisher/. moda etc. But anyhoo why cant you have a 5m deep v? . I cant find a single one advertised. Look at formosa/ tabs etc. I wouldn't go out on one. Why isn't there an equivelent of a haines v17 for example?

[scottar]

Take a look at Sea Adex or Ocean Cylinder if you are after a big deadrise. Like all things in boating everything is built to a compromise. Maybe some of the issues you have outlined yourself simply mean that without other design features to compensate (primarily the pontoons for at rest stability) simply make the characteristics of the size hull your after impractical.

[Lovey80]

Or just build an ally cat. You get better ride and stability than either a shallow or deep dead rise mono. I recon I'd rather have a 5.3m ally cat with a single engine and tabs than any mono on the market today.

[KingyKing]

Take a look at Sea Adex or Ocean Cylinder if you are after a big deadrise. Like all things in boating everything is built to a compromise. Maybe some of the issues you have outlined yourself simply mean that without other design features to compensate (primarily the pontoons for at rest stability) simply make the characteristics of the size hull your after impractical.

But so so ugly expectably the Sea Adex. For me it's the Pelagic boats all the way, Ive been speaking to them about a 6.5m - 7m and nothing seems to be an issue they can and will pretty much build anything you want it just comes at a price. we spoke a lot about deadrise and he's answer was "when we design a new hull we always aim for the highset deadrise possible we can be somewhat restricted when going into survey but have a little more room to go up in deadrise under the rec boat standards". The only down side is they might not be making their stepped hull available to the recreational boating market
Ive been watching there 28 stepped hull build closely and from what ive been told from people operating there 6.5m Coastguard boats is that they have the ride sorted and rival some highly respected glass hulls.

[Crunchy]

Saw a Moda at the Nudgee servo yesterday (Might have been one you blokes?) thought it was a glass boat form a distance from the shape and the finish, geez it was nice.

[Chris Tucker]

Deadrises are definitely on the increase, when I first joined this part of the industry about 10 years ago the typical plate boat deadrise was 12-14 degrees. Now it is about 16-18 degrees

As mentioned by Davidson above, one of the biggest drivers is actually the desire for self draining decks. This seems to be a bigger priority to plate boat buyers than it is to glass owners. Raising the deck 150-200mm and the gunwales with it has a huge effect on stability. Lose that one simple feature and you'll see an increase in deadrise without the loss in stability. This is exactly what we've done on the new upcoming range from Hammerhead.

The 5.3 Dragon fly we keep coming back to was one of the first boats I designed for Hammerhead. At the time I'd just finished designing the Boab Boat Hire range of boats that look and perform similar to pleasure boats while still being fully survey compliant. As his company was young I steered Gerard towards a product that could be sold as a good pleasure boat while still be able to be put into survey with reduced passenger numbers (which a couple have) to increase possible revenue streams. .

Over the years his company has developed to the stage where 90% of his work comes from pleasure boats with the rest from survey. With this in mind we now keep an eye firmly on the pleasure boat user and then design custom commercial boats for him when and if necessary. The new 5.3m Dragonfly while built to survey standard no longer has the survey stability of old model allowing for a softer more aggressive ride.

Lovey80. You might be interested to know the deadrise on my standard 7.5m cat hull is 20 degrees.