Dive RIB Build From Scratch - What to Copy?

[CodeS]

So, I want to build a boat. My main trouble is that I don't have much boating experience so I don't know what boat is going to be best for me.

I have a pretty well equipt fabrication workshop, so from a construction standpoint I'm good to go.

Let me tell you about a few of my requirements, and then what I am currently thinking. Here is a list:

- Be light to tow long distances (as it will be mainly used on trips away up/down the NSW coast)

- Fit 3 divers with heavy, technical diving gear.

- Be able to travel offshore, in NSW Australia, upto 20km trips each way.

Currently I am thinking a 5-6m Aluminium RIB with hard foam collar with a 90hp + outboard. I am thinking a hard foam collar is going to be the easiest thing for me to build.

So my questions are:

What would you build (with photos and rough measurements if at all possible)?

What would something like what I describe weigh?

Any other information you need from me?

Any questions I haven't asked?

Thanks in advance.
CodeS

[Pete7]

Put the console at the stern so there is a shed load of space up front for kit and getting kitted up. Don't under estimate the room you need for all the kit so I would choose 6.5m plus. You will want 200 hp or more to make it move.

Presumably you are building in Aluminium? it that case make the tubes out of aluminium too, rufty tufty techie divers won't mind as they can stand up when travelling at speed.

That is going to come in at about 1200 kgs on the trailer. Are there any towing limits or tow vehicle?

Pete

[GuyC]

There's a few ideas on this site.

Aluminum Landing Craft - Workboats | Aluminum Boat Plans & Designs by Specmar

As Pete7 has suggested I wouldn't narrow it down to just a RIB.

If it is used commercially, it may need some form of certification from your version of the MCA which I think is the AMSA. You might find your welding needs to be approved. You would need to check with them to ensure any plans you have will meet with their requirements. It's much easier at the drawing stage to change things than at the build stage.

I agree with Pete on the weight but you would also have to factor in the dive gear and kit if you are carrying it in the boat.

[Pikey Dave]

Don’t forget that you have to get the divers back in the boat. You might want to consider a lift.

[Pete7]

Originally Posted by Pikey Dave

Don’t forget that you have to get the divers back in the boat. You might want to consider a lift.

3 months of gym membership for the crew would be easier. I can remember watching a middle age techie struggling to carry her rebreather down to the boat in Portland. It didn't inspire confidence if something went pear shaped.

Wasn't like that in my day

[CodeS]

Originally Posted by Pete7

Put the console at the stern so there is a shed load of space up front for kit and getting kitted up. Don't under estimate the room you need for all the kit so I would choose 6.5m plus. You will want 200 hp or more to make it move.

Presumably you are building in Aluminium? it that case make the tubes out of aluminium too, rufty tufty techie divers won't mind as they can stand up when travelling at speed.

That is going to come in at about 1200 kgs on the trailer. Are there any towing limits or tow vehicle?

Pete

Thank Pete

Yes I am thinking about an Aluminium build. Not locked in though if I can save on weight, but I don't think that is the case.

I have a Navara and can tow 3t safely. My main issue is that I'll be doing long trips with it, so any weight/drag saved is a good thing.

The aluminium tubes had crossed my mind, my only thought was increased weight with possibly not much advantage.

Originally Posted by GuyC

There's a few ideas on this site.

Aluminum Landing Craft - Workboats | Aluminum Boat Plans & Designs by Specmar

As Pete7 has suggested I wouldn't narrow it down to just a RIB.

If it is used commercially, it may need some form of certification from your version of the MCA which I think is the AMSA. You might find your welding needs to be approved. You would need to check with them to ensure any plans you have will meet with their requirements. It's much easier at the drawing stage to change things than at the build stage.

I agree with Pete on the weight but you would also have to factor in the dive gear and kit if you are carrying it in the boat.

No commercial use intended. I did have a look throught specmars site but couldn't work out what the final weight of the boats would be.

Originally Posted by Pikey Dave

Don’t forget that you have to get the divers back in the boat. You might want to consider a lift.

I am thinking a small hoist to lift the gear in, and about a deck out the back. In the past I've just taken my gear off and passed it up, wasn't a big deal.

Originally Posted by Pete7

3 months of gym membership for the crew would be easier. I can remember watching a middle age techie struggling to carry her rebreather down to the boat in Portland. It didn't inspire confidence if something went pear shaped.

Wasn't like that in my day

I shore dive here in Sydney, lots of stairs each way up and down a cliff. I can't say I've ever seen someone struggle walking to a boat

[CodeS]

I have been loving the look and design of the 'life proof boats' range like attached. As I understand they use a foam collar vs fabric tubes. I'd only be able to budget for a much smaller version however (which they don't build).

Anyone have any idea on towing weight on a 5-6m version of these (even an educated guess)?

[Maximus]

You say you don't know much about Boats ...or Boat building Well I'd say that's where to begin!
As for your plan That's a pretty Gargantuan task (that would make most experienced Boat builders pale...) you have set yourself there Mate!... With MANY design/engineering/technical/safety and logistical problems to solve before you get anywhere near the Water!...Hey if you (eventually) see whole process through to a successful conclusion I for one would commend you're efforts
But having seen the well established Pro's efforts to copy a an already existing..successful RIB design in Alloy with everything at hand and with the considerable recourse of the defence industry behind them I think there are better options than starting from absolutely Scratch
A ground up refurb of an already proven design would be the first....with the considerable Bonus that will know exactly if that Boat meets all your criteria before you embark on what may well turn out to be a blind alley (or several)...indeed you may well be able to trial a completely serviceable example...more so if,as it sounds you're thinking along commercial lines.
You may be able to convert a Tubed Hull Alloy Boat to Solid.if that's important to you...(Although plenty of Divers have used inflated tubes for years) You may be able to source an ex Military Alloy Boat at auction to suit you're needs or one which you can modify...ect
It just seems to me you're making a big Rod for you're own Back...whith other much simpler..cheaper..less time consuming...and Brain Damage. Inducing effort..than you need to embark on.
I don't know your position or financial standing. But If indeed you do have the considerable skills and equipment to make you're own RIB from Scatch....Id have thought the Private Fabrication route...i.e doing some fab work privately for clients would soon enable you buy a decent example of Dive RIB to further your stated aim of actually getting on (or under) the water.
Either way Good Luck!
And Please keep us Posted.

[Pete7]

Originally Posted by CodeS

I shore dive here in Sydney, lots of stairs each way up and down a cliff. I can't say I've ever seen someone struggle walking to a boat

A well balanced 6 - 7m rib will tow at 50-60 mph quite happily for hours so long as the wheels doesn't fall off. Not an unknown event in the Solent area

http://www.rib.net/forum/f8/ribnet-m...ing-13952.html

This was our training dive location. If you could carry your kit down and back again afterwards from Durdle Door, you were likely to be invited back again. Some wag counted 350 steps from the car park next to the caravan park to the beach on the left. There was supposed to be an ice cream van that would carry your kit for a few quid. Never there when we dived it. To old for that malarky now, instead we just sit back with the autopilot on enjoying a G&T. AIS keeps everyone out of our way so we can concentrate on reading a book or watching You Tube whilst under way

Have to agree with Max, refurbishing even a shell would be a lot easier and you have a known hull to start with.

Pete

[Pikey Dave]

Originally Posted by CodeS

I am thinking a small hoist to lift the gear in, and about a deck out the back. In the past I've just taken my gear off and passed it up, wasn't a big deal.
:

Ah right, not real techies then[emoji6]
I wouldn’t want to be hauling rebreathers/side mounts/deck drop bottles back over the side of an ally tubes boat. I used to clip my kit onto the lifeline of the RIB, climb in & then haul it all in, bloody hard work & that was with soft tubes. I wouldn’t want to be doing it x 3. I certainly wouldn’t do it in anything but calm water.

[Poly]

Originally Posted by Pete7

Have to agree with Max, refurbishing even a shell would be a lot easier and you have a known hull to start with.

Whilst these two are talking a lot of sense an aluminium home build run project would be amazing to follow on here! Personally if I was doing it I’d get tubes from a professional, foam tubes would be a lot of work for a one off, and I assume that the cost of material for Marine grade Ali tubes would be enough to make you pause for thought?

[Ribtecer]

I would enjoy the thread I must say.

Putting sealed hatches in the alley tubes for additional storage would be handy, I'm thinking fenders etc., nothing too heavy.

[lakelandterrier]

I agree with Maximus - massive undertaking - especially if needing coding or local equivalent. I'd also say massively expensive as a one-off. A refurb / adaptation would surely be better / more practical?
Love your ambition, and do keep us updated on whatever you do

[jonp]

Firstly being a Pom who has now lived in NSW for the last 25 years and owns boats the entire time, I can honestly say boating conditions are quite different from owning and using boats in the UK. Even though I had worked on trawlers, charters and even a French crab boat I was quite shocked to experience how different conditions are with almost daily Sea breezes of 16-20 knots and swell conditions that keep our coast here pumping with good surf. Then there are the rough days.

Since being here I've owned all kinds of boats and also get the opportunitys to drive some of the best rough water handling boats this country has on offer. I currently drive dive, abalone, urchin and small research boats . Ive also worked with volunteer rescue groups here over the years, so again get to use a variety of boats.

Some of the aluminium boats such as stabi, ocean cylinder etc are quite hard riding and pretty noisy. I'm far from being a fan of aluminium boats as they can suffer so easely from galvanic corrosion problems. Simply fitting sounders, radios and rod holders can cause issues. Using silicon sealants also needs to be carefully chosen as acids from the silicon can harm the aluminium as can fishing weights or rusting hooks. Many of the new aluminium boats are now being made from cheaper aluminium from China, which are showing extremely poor corrosion problems. One of the big guns with these problems seems to be naiad if reports from two of our new rescue boats are correct. These boats are also very heavy, one i recently drove from maritime was powered with a 250 suzuki on just a 5.8m boat. This is far from light and economical in my opinion ( just price a 100 hr service on a 250).

You mention tec diving 20km offshore, where here in Narooma you would be in 500-600m of water ( so extreme tec diving). Even off Sydney 20k offshore puts you in very deep water.

When I was looking for a rib I decided on a 550 pro in the newer hull configuration that has wider strakes which allow for better handling and the ability to be powered with smaller lighter economical engines (Yam f70). This gave me a fuel burn of around 3km per litre of fuel and a 100lt underfoor fuel tank. Offshore runs of over 200k in a day I have felt safe and confident. Towing is a breeze. Mine ( only for a few more days as it's now sold) has slightly smaller 50cm tubes which makes swimming over the side easy once out of dive gear. If I was to use the boat for more regular scuba I would invest in heavy tube covers which are around $1500-$1700 and permenantly stay attatched.

The fact I can remove a tubeset virtually on my own would make replacing tubes pretty straightforward in the future. The 550 can legally carry 12 adult passengers in Australia ( which is crazy!!!). Being fibreglass with no wood in the build means no worry s about rotting transomes or floors etc.

Selling this boat has been the toughest decision I've made with any boat, it's truly been the most fun boat Ive used. We don't have the same variety of ribs the UK has so I can only say I prefer mine from the three manufacturers I use.

I had considered a comercial vessel as my next punches but government charges and insurances once you put people in the water simply make it not worth while. Having back and neck injuries I'm now considering going back to a boat with seats and an ellectric anchor winch.

[jonp]

One more thing, check out Yamba welding who make ocean cylinder boats ( used by police, rescue and even Sydney aquarium etc).

This boat would of been the perfect boat for me but timing was not to be and I missed out on it. Built with aluminium tubes, even side and rear removable dive doors and heavy lifting hoist with ellectric winch. It had several considerable price drops before selling.

[CodeS]

Originally Posted by jonp

Firstly being a Pom who has now lived in NSW for the last 25 years and owns boats the entire time, I can honestly say boating conditions are quite different from owning and using boats in the UK. Even though I had worked on trawlers, charters and even a French crab boat I was quite shocked to experience how different conditions are with almost daily Sea breezes of 16-20 knots and swell conditions that keep our coast here pumping with good surf. Then there are the rough days.

Since being here I've owned all kinds of boats and also get the opportunitys to drive some of the best rough water handling boats this country has on offer. I currently drive dive, abalone, urchin and small research boats . Ive also worked with volunteer rescue groups here over the years, so again get to use a variety of boats.

Some of the aluminium boats such as stabi, ocean cylinder etc are quite hard riding and pretty noisy. I'm far from being a fan of aluminium boats as they can suffer so easely from galvanic corrosion problems. Simply fitting sounders, radios and rod holders can cause issues. Using silicon sealants also needs to be carefully chosen as acids from the silicon can harm the aluminium as can fishing weights or rusting hooks. Many of the new aluminium boats are now being made from cheaper aluminium from China, which are showing extremely poor corrosion problems. One of the big guns with these problems seems to be naiad if reports from two of our new rescue boats are correct. These boats are also very heavy, one i recently drove from maritime was powered with a 250 suzuki on just a 5.8m boat. This is far from light and economical in my opinion ( just price a 100 hr service on a 250).

You mention tec diving 20km offshore, where here in Narooma you would be in 500-600m of water ( so extreme tec diving). Even off Sydney 20k offshore puts you in very deep water.

When I was looking for a rib I decided on a 550 pro in the newer hull configuration that has wider strakes which allow for better handling and the ability to be powered with smaller lighter economical engines (Yam f70). This gave me a fuel burn of around 3km per litre of fuel and a 100lt underfoor fuel tank. Offshore runs of over 200k in a day I have felt safe and confident. Towing is a breeze. Mine ( only for a few more days as it's now sold) has slightly smaller 50cm tubes which makes swimming over the side easy once out of dive gear. If I was to use the boat for more regular scuba I would invest in heavy tube covers which are around $1500-$1700 and permenantly stay attatched.

The fact I can remove a tubeset virtually on my own would make replacing tubes pretty straightforward in the future. The 550 can legally carry 12 adult passengers in Australia ( which is crazy!!!). Being fibreglass with no wood in the build means no worry s about rotting transomes or floors etc.

Selling this boat has been the toughest decision I've made with any boat, it's truly been the most fun boat Ive used. We don't have the same variety of ribs the UK has so I can only say I prefer mine from the three manufacturers I use.

I had considered a comercial vessel as my next punches but government charges and insurances once you put people in the water simply make it not worth while. Having back and neck injuries I'm now considering going back to a boat with seats and an ellectric anchor winch.

Jon, I think you have hit the nail on the head. That's exactly the type of thing that would fit my purposes. Light and seaworthy, making long distance trips a bit more practical for me.

I think an aluminium build will add up in weight (especially how I wanted to do it). Do you know the dry weight of your Zodiac there?

The diving I do is not that seriously technical. Twins or sidemount and certainly in Sydney nothing deeper than 30m, maybe 40m if I go away. I like the macro critters and there just isn't much to see deeper (other than sunken ships #yawn ). I didn't mean 20km in a straight run east (closer to 10km I think).

So looks like I may be learning a new skill for this after all :P .

[Bigtalljv]

I love the DIY mentality, I’m on my second boat refurb, a hard boat this time, a 7m military zodiac the first, but I’m not seeing your need.

You stated that you don’t have a ton of experience boating, I think you need to rectify that first. Your needs are not earth shattering, many common boats should get you going. Buy one and learn. Odds of getting a custom boat right without the experience are slim and it a very expensive way to learn.

Jaso

[jonp]

Originally Posted by CodeS

Jon, I think you have hit the nail on the head. That's exactly the type of thing that would fit my purposes. Light and seaworthy, making long distance trips a bit more practical for me.

I think an aluminium build will add up in weight (especially how I wanted to do it). Do you know the dry weight of your Zodiac there?

The diving I do is not that seriously technical. Twins or sidemount and certainly in Sydney nothing deeper than 30m, maybe 40m if I go away. I like the macro critters and there just isn't much to see deeper (other than sunken ships #yawn ). I didn't mean 20km in a straight run east (closer to 10km I think).

So looks like I may be learning a new skill for this after all :P .

My hull is 315kg, Yamaha f 70 119kg, 100lt of fuel roughly 100kg. Load carrying performance comes down to prop choice but having a smaller pitch for days when you carry large amounts of gear and a large pitch for light loads is an easy fix. I tend to stay with the smaller pitch all the time so I can keep the speed and control working in bigger sea conditions better.

As for small critters, nudibranchs etc, Ive found a few amazing spots here ( Narooma ) out at Montague that have amazing varieties where people never dive. People here only want to dive with seals or grey nurse sharks.

Using sidescan and downscan truly opens up a heap of fantastic diving opportunities before you even get in the water. I can easely find exciting new spots just from using my sounder. This spot at Monty drops to a mere 18m with boulders and rocks at 8-10m and incredible fish variety and life.