I'm looking for a new offshore boat, in the 7.5m to 9m range. Below are my criteria/thoughts:

http://trademe.co.nz/motors/boats-marine/motorboats/auction-735801240.htm" rel="nofollow - http://trademe.co.nz/motors/boats-marine/motorboats/auction-735801240.htm

My problem with it is there is 40k of bling on it and as someone who is only in the country every other month, due to rotational work overseas, I find it hard to justify throwing that extra 40k at it for something that is not used nearly as much as it could be.

Still, I might go and have a look at it.

Thanks for the responses from the others.

I like the idea of the electric over hydraulic steering. I guess this means I could easily mount remote steering outside the wheelhouse too.

Ultimately, I do think I will be getting something more towards the upper end of my size range, rather than the lower end.

I would buy a small dive compressor and somehow fit it into the engine compartment, getting rid of the bulk of the weight of the compressor drive motor.

Not sure whether this is practical, but being a mech. engineer, I like to think something like this is totally achievable.

Re the Dickey Boats, yes, they're very smart, but as I said before a lot of dosh tied up that isn't used enough. Pretty hard for me to justify whilst I'm working offshore.

Wasn't aware that you had to be approved to fill your own cylinders at home - the bureaucratic reach never ends in this country.

I know a number of people with their own compressors, who fill their own and others bottles, I'll guarantee not one of them is "approved".

I recently had a licensed gas fitter at my house, and he scared me, grinding next to a disconnected live gas line, with only single point isolation of a poxy cheap ball valve. I guess he was "approved" too...

1) Sucking in clean air to the compressor - not to much of a problem if running an outdrive or underwater exhaust as the suck in point can be a lot higher on the boat.

2) Cooling - most air compressors are air cooled so need really good airflow round them.

This is a problem for my boat as I want to install below deck, so working out how to get the additional air down below.

3) Cooling the scuba bottle is not a problem as the size compressor which will be used is 20 to 40 minutes for a fill. Ideally you want to be filling bottles when cruising between dive spots. My plan is have the bottle strapped on the stern platform when filling. 

4) Driving the compressor - electric options with large inverter seem to be very popular - you need to run the main engine. Hydraulic drive is very effective and quieter. petrol driven compressors - I have used on deck (not below) are noisy and I do not want to be carrying petrol. 

5) Lastly costs - installing a baby electric drive Coltri is around $8k.....

So it is on the wish list but not there yet

V10 Touareg chipped to 1000Nm... sounds like a quick way to blow the transmission apart. Even standard they are prone to trans failure

We never used a cage for filling our dive bottles onboard the boat nor do any of the commercial dive operations in the Bahamas. I'm not saying that is right but just saying it is done.

For dive bottles a multistage compressor with a pressure of 3500 psi is about right.

I do like the thought of having  a shaft drive, but not sure if it will work with marine gearboxes.

Mattyroo, like the thought of a water cooled compressor - should be a lot quieter. 

Who makes small ones?

I know many truck gearboxes are fitted with them. 

If you had a PTO shaft from the gearbox to a compressor or hydraulic pump it would be quite efficient.

Why a no oil compressor?

I only cruise at 10 knots so there is no performance loss.

The big problem is the bottle you want is in the bottom of the hold and shifting all the others on top!

Pig of a job if there is any swell.

mozz wrote: Don there was a guy in the next marina down running a compressor off his volvo engine for his tanks and I remember him mentioning Vanair so maybe it was not an off the shelf model or maybe he just used parts from them

This is another way of doing it which I have considered, but the air amplifiers are pretty damn noisy and consume a lot of air.

These guys modify the Bauer compressors and have a couple of different sizes.

http://lauderdalediver.com/dive/dive-compressors/ns450-water-cooled-dive-compressor

I like the idea of water cooling and then water cooling the interstages. Watercooling the interstages will certainly reduce a lot of pulsation noise, which is the worst noise. As they only watercool the heads and not the cylinders, I don't think there will be a huge reduction in noise from the compressor itself.

Yep, this is absolutely the ideal way to do it.

My thoughts on how to do this are split;

1. Running a hydraulic system will make for a nice less complicated install

2. Gives me added benefit of powering other systems with hydraulics, such as a simple divers lift design that I have come up with. A very non-obtrusive design, unlike many that are out there.

3. The problems with a hydraulic divers lift is that the engine must be running to operate. Nobody wants to do this.

4. Running a standard electric powered compressor off an inverter

5. If I was to have a compressor off an inverter, I could power my divers lift off air. On air of 120psi, I can lift approx 200kgs. I would have to devise a way to take LP pressure off the dive compressor (this will be easy enough), then, have a storage cylinder (not wanted at all) and probably run the motor, due to the load on the battery from the compressor through the motor. Again not ideal. This will take me some significant calcs to workout whether I can run the compressor off the battery to only produce LP air for the divers lift.

Absolutely this is an option, but we're serious divers and a few days away with 4 divers this isn't many dives a day. It certainly is a valid point, but my main aim is to be able to supply sufficient air for four divers for say four days - this could be very conceivably 32 bottles/fills.

Why a no oil compressor?

When I built my boat we left a big hole in the transom

It is still a challenge to get on board.

I think you have the same check list I have for the compressor.

It will be either hydraulic or 240 volt electric for me - I have been looking at a Coltri with local support.

http://www.airtec.co.nz/

The water cooled Bauer looks interesting 

Good luck with your build

There is some merit in that suggestion, which, of course, I have thought about. For me, working offshore and not being in the country less than 50% of the time, I really want to be able to just grab the boat and take it down to the Sounds, up to the BoI, out to the East Cape. Having to come back and then motor to these places, is not really what I want.

We also like to load the boat and go and camp with friends in very remote places, yes this can be done with a launch, but not with the same flexibiity.

As this project is evolving and my research etc. gets. more detailed, I now expect to spend a bit more and probably make the boat a little more comfortable.

Could be a possibility, but not sure that a DC motor capable of running that will have a duty cycle long enough. Might make an enquiry.

Mozz and Mike many thanks for those links, might be quicker for me to get up and running.

Mattyroo, you are correct a trailer boat does give you alot more flexibility to travel the country.

I chose to put the trailer money into a marina berth and go everywhere on my keel.

My boat cruises 9 to 10 knots, so it is 8 to 9 hours from Auckland to the Knights, 6 hours to the Mercs and 4.5 hours to the Barrier. But I know that many other boats only cruise at this speed so do not feel not hard done by. I decided I did not need a big 4X4 to tow the boat.....

Good thread this one.

Your fuel tanks are along the C/L, one forward and one aft? Inboard/outboard?

Was looking at one large fuel tank just forward of the centre mounted donk. Maybe consider splitting the tanks.

Good point about having a pump in the bottom of the tank to empty, for an extra $100 or so, a simple but effective addition.

Rather keep other underdeck areas for space. 

For long road trips, have you considered a bladder tank, that you could carry on your ute(if you have one) or forward in the boat, then just transfer when required?

A 5kW AC generator set belt driven by the engine, this will provide the required AC power for the compressor. I will have it engaged through an electro-magnetic clutch.

I think if i'm going to spend in excess of 6nicker on the compressor, I want to be able to remove it from the boat and run it in the shed at home too, therefore, any hydraulic or direct drive compressors I think are out. Only thing with it, it needs quite a high speed to deliver 5kW (6500), but can deliver 4.8kW at 4700 rpm - just have to make sure the pulley ratios are correct to get adequate speed without revving the tits off the main...

I just now need to verify that this set will cope with the in-rush of my selected compressor, but with 85A in-rush, it should do the job - although I need to verify this as the technical doc states an in-rush of 85A and the web page states 40A....

The other good thing about this is the capacity to run other 240vAC circuits that may carry a load.

Looks like the boat will be a 9.5m full lock-up, with 8mm hull. It will likely be reasonably highly specced and have the ability to carry ~1000 litres of liquid (fuel and water). We will carry a bit of weight at times, 6 people, dive bottles etc...

Thoughts are;

Pros:

Reliable

Easy to get parts and service

Good power-to-weight

Cons:

Expensive

Parts and Service expensive

Pros:
Much cheaper than the Volvo

Parts and service relatively cheap - parts should continue to get cheaper and be readily available, due to the wide range of motorcars running around with these in them

Cons:

4.2l has its neck wrung off to get 370HP

Lightweight

Not yet a reputable engine that one can be sure of reliability wise, with this sort of rating

Any other pros and cons of those two, that others can offer?

Other engine recommendations? I could go for twins, but not really that keen on twins. Definitely will be inboard and will definitely be diesel.

Mercruiser Bravo outdrives and some excellent Japanese engines.

Straight six; http://www.whitingpower.com/products/marine-engines/power-boat-engines-yanmar/yanmar-lpa2-series-sterndrive-(315mhp)

V8; http://www.whitingpower.com/products/marine-engines/power-boat-engines-yanmar/yanmar-8lv-series-sterndrive-(320-370mhp)

Why not the V6 Mercruiser TDI.  This is what will be in my Tristram Grandeur.  Seems to have great reviews.  Not sure how heavy your boat will be but the Grandeur is 3 tonnes plus and has test data suggesting 25 knots cruise at 25 lph and WOT near 40 knots and 54 lph

I don't think that is enough HP for a boat of this size, that will be going offshore. Even Tristram recommend a minimum of 300HP for the Grandeur - but then go and put the 260HP in as standard...

Might as well just go for a Wärtsilä 18V46 then.... Why not???

You know what a Turbo specialist told me when I needed parts for a variable vane turbo on on of our Volvos? "You mean the silly buggers put that on a marine engine".

Just a word of caution that all this high hp and sexy design to make a lightweight diesel perform comes at a cost. The cost is that that engine will not last like people think a diesel should last, and the maintenance costs are likely to be scary once the hours get up. I love diesels, but I have reservations about putting the very complex modern lightweight ones in trailer boats. 

Maybe.

Pros of a shaft drive are;

Wider engine range - therefore possibly lower ongoing costs

Cheaper installed cost

Cons:

Slower

Fuel burners

Noisy

Vibrate like hell due to the cardan shaft

Much more difficult beach launching

On a trailer boat, a slightly wet bilge and salty atmosphere around the engine is usually a certainty. Not a happy combination with parts that may have been designed for a car or truck.

 

They are physically bigger and heavier engines though than the VW and V8 Yanmar.  The Yanmar V8 is actually a Toyota block out of the 200 series landcruiser complete with twin turbos and titanium lined bores - light weight but not designed for marine service duty ratings imo.  Then there is the servicing aspect and what happens if something does go wrong - I can understand my boat engine, do a lot of the servicing myself and feel confident I could deal with most solveable problems that might eventuate on the water.  I only feel competent to check the oil and water on my Landcruiser and tdi Volkswagen car though. 

 

I'm with Tagit on the hp/l of displacement matter and think that these new generation lightweight VW and Yanmar packages will have short lifespans compared to what they replaced.  Both engines are stretched to put out more HP than their motor vehicle clones and then expected to maintain 80% HP and max torque for hours on end which is a stark contrast to what is expected of a lightly loaded car or suv engine.

 

I like the Bravo 2x leg for its simplicity, robustness and ease of servicing also and consider the performance compromises compared to duo prop legs a worthwhile sacrifice.

 

It's going to be a 9.4m aluminium launch, with 8mm hull. Volvo D6-370 will be the ponies.

800 litre fuel tank. Sleep 6. Enclosed wet head. Twin station. 5kW power system and inverter to drive dive compressor - will be able to run the dive compressor for 30 mins off the batteries alone. Separate hydraulic power system (12vDC) for divers lift.

Hopefully will be all complete mid-2015.

Will still tow it. Will probably import a reasonably late model F-350 dually and convert it. Can pick tidy mid-late 2000s up for under 20nicker US.

 

I am 8.3 plus platform and I reckon I could build a boat to work well for me at 9m but it would go out in width from my current 2.8 to 3m.

 

I would suggest if it's going on a trailer it makes a big difference the loss in width most trailer boats have.

 

Ergo you would have to add length but it never works quite the same.

 

Find a Genesis pro fish if you can do without the trailer and go anyplace you want (my dream boat).

I'm pretty keen on the idea of through hull and will probably go for the Simrad BSM-3 and the B265LH transducer. I could always go up to the R509LH Tx and BSM-2, but this option is ~2k more and whether I really need that is debatable, other than to have the best.

Anybody been running either system? Any feedback on these?

We're having Makaira Boats build us a King Bank 940. You may have seen the thread on here from Spectrum of the one he has recently built for himself. This is an awesome boat and I really like the design and the attention to detail that Spectrum has put into it. Hope to have it totally finished for the Spring time.

We elected to go for an 8mm hull and it will be powered by a Volvo D6-370. It will be finished to a reasonably high standard and have some pretty unique features for a boat of this size, including a hydraulic divers lift. Hydraulic supply will be from a 12v HPU mounted under the deck. We're also going to have 5kW of AC power available to run a small dive compressor.

 

When you guys order a 940 or an 850 is that waterline length or over all incl fairlead and platform?

I know with trailer boats you used to have to put a tape on them because it varied between builders.

Perhaps this is standard now in the industry or I never figured out something pretty simple (again).

When one of you guys with a Makira come north give me a shout I would love to take a squiz.

I know when I tow my 9m (overall) boat home it is huge on the trailer, you are going to draw some interest from the masses!

Good luck with the build, I watch with interest, sounds, looks super.

I am after a new 8.5 /9.0 mtr boat. Budget is around $200k possibly $240k.

 

But, for that money you certainly should be able to get a boat built in the 8.5m to 9.0m range. It won't b fitted with a lot of bling, but you'll certainly have a nice, comfortable, functional boat.

I meant are new boats over all hull size or over all size including all overhangs, sprits, platforms etc?

I realise now platforms are pretty much part of the hull in most cases and less of an add on than they used to be.

When my boat was ordered (i have the build sheet) they purchased the hull and engine package and then added the deluxe anchor fairlead and pulpit and then the swim platform as extras as well as electonics etc.

 

I very much believe it is up to each individual manufacturer. For this boat the 9.4m is measured from the tip of the bow (without fairlead) to the rear of the transom.

Very nice indeed. Impressed.

Like the shape of the hull very much. Big volume vessels.

Think I am leaning to the 8.40 option due to budget.

was looking at white pointers but since seeing these I may have changed my mind.

dickey boats are nice too, but only 2.5mtr beam. that extra 300mm-400mm width is a lot.

nothing in it budget wise. Think these will handle a good sea on the west coast.

 

Cheers.

I may be biased, because I'm having a Makaira built, but I think they're one of the best designs out there. Great looking, extremely rigid, due to the full-length chassis rail type design and the finishing detail is top-notch. I guess what sold me, was it was very easy to see Allan's attention to detail coming out in the boat.

Honestly, I don't think you can go wrong if you go for one of these.

I do like the very tall bow

Being an engineer in the offshore O&G industry, I do like strength, and it doesn't come much stronger than the below...

Will hopefully get some more shots next week. Progress should be well advanced.

I've had lewmar thrusters on a couple of smaller 30ft boats and they have been more of a hassle than anything(thruster tunnels cracking, black box burning out,dash controls breaking). Unless you are docking solo a lot?

Hull looks like a beast!

Fitting a thruster for a number of reasons; heavy, high windage, ease of docking etc. especially as only one screw.  Fitting a Sidepower 2.2kW job.

Hopefully don't have any of the issues you mention.

 

My boat is about the same size with nothing like the height in the bow and on windy days they do blow down pretty fast.

If a thruster was reliable I can see one helping at times in a boat with this much windage forward.

Sometimes I must look like a real clown because i power in pretty fast on a 45 to the dock and pop it into reverse pretty late and slide the stern around when it's blowing a certain quarter.

Doesn't pay to think about how it's gona look if reverse doesn't happen, so I don't much.

Only a couple of times a year but still.

Gotta love duo props when you are jinking around fuel docks etc.

I would guess my boat to be way lighter forward though.

 

Will these boats be at the on the water boat show?