First boat design and build

[Adam Smalley]

About me

Since I was a kid I have enjoyed DIY and making things. I don’t have experience in boat building so I don’t feel comfortable building entirely from scratch, so I am considering buying a basic RIB or SIB and modifying it to add some features for fishing and comfort whilst improving the aesthetics. I intend to use this as a gateway to more complex projects. It is my dream to one day build a houseboat.

Specification

• It should fit in a car (preferably in the boot).
  
  
• It should have a collapsible shelter that covers the boat. This should be in two parts to enable the stern to be covered whilst the bow is exposed.
  
  
• You should be able to sleep in it.
  
  
• It should be able to carry a minimum of 4 people, preferably 5.
  
  
• Chairs should recline.
  
  
• It should be able to go at least 20 knots with 2 people in. Though ideally I would like to go faster.
  
  
• Fuel efficiency is one of the most important factors. It should ideally use less than 10 litres an hour. I’m not really knowledgeable enough to know what is realistic so I would be grateful if someone could explain what is realistic and give me any tips on how to design a fuel efficient boat.
  
  
• It will be used for fishing so if it has an air floor it should have some sort of protection from sharp objects.
  
  
• It should be seaworthy in F6 winds. I would ideally like it to be able to cross the English channel in good conditions.
  
  
• It should have nav lights so it can be driven at night.
  
  
• It should have decorative lights on the floor and underwater.
  
  
• It should have powerful enough lights so the deck is fully illuminated at night.
  
  
• It should have fishing rod holders (at least 5).
  
  
• It should be modular, to enable parts to be emitted if they are not needed. This is to enable a quicker setup and lighter load for shorter trips. E.G some of the chairs and tent could be emitted for day trips.
  
  
• It should have plenty of storage space. Enough to store a folding bike.
  
  
• Should have a waterproof storage compartment for electronics
  
  
• It should have trim tabs.
  
  
• Fishing rod compartment
  
  
• Anchor
  
  
• Cup holders
  
  
• Wireless phone chargers
  
  
• Vinyl floor (for aesthetics)
  
  
• Refrigerated separated fish and drink storage compartment
  
  
• Everything should be controlled by a computer which can be controlled through mobile phones. The computer should have:
  
  
  • Autopilot
    
    
  • Mobile signal booster
    
    
  • Networking
    
    
  • An alarm
    
    
  • Chart plotter
    
    
  • AIS
    
    
  • Fish finder
    
    
  • Ability to control lights
    
    
  • Be able to display engine data and fuel level
    

Budget
£3000-£5000

Design ideas so far
Sketch

Note: This is designed so it can be taken down into smaller parts for transport. I realise this will be very cumbersome to fully assemble and take apart but that it is ok with me. The rear chairs and front deck will flat pack. They are designed so they can be omitted for shorter trips.

1. Fuel Tank - The fuel tank will be in a compartment in the storage area below the reclining sofa bed.
   
   
2. Helm - Will have manual steering as well as an autopilot based on pypilot. The autopilot will turn the steering wheel using a truck motor. An example of this demonstrated by the developer of pypilot here.
   
   
3. Manual Throttle and Ignition - Pypilot will be modified to enable it to control the throttle and start the motor. These manual controls will override pypilot if used. I have not decided exactly how this will work yet.
   
   
4. Display and Raspberry Pi - The boat will use a Raspberry Pi running Debian Linux and openmarine as the main control system. I am looking into modifying it as my friend (who is helping me) and I have a background in software engineering, but I have not decided exactly what changes to make at this stage. It has been created for sailboats, so it might be best to do some mods for motorboats, but it looks like it can run a motorboat out of the box. This will be located in a water proof container that will also contain the other electronics. This will be connected to a display below the helm that will act as the main interface to the boat's control computer. The boat control system will also have a headless interface, that can be accessed on devices, through WiFi or over the internet through a 4G connection, built into the boat.
   
   
5. Charging Compartment - There will be a waterproof compartment to store and charge phones and other electronics.
   
   
6. Front Navigation Light - Combined red port light and green starboard light.
   
   
7. Bow Tent - A custom made tent to cover the bow. It is designed to keep bad weather out and provide shelter at night when people are sleeping on board. It will have an outer fabric to provide weather protection, a frame built from PVC pipes and an inner insulation layer that will cover up the PVC pipes.
   
   
8. Stern Tent - The other half of the tent. The two tents will cover the whole boat.
   
   
9. Motor - I’m not sure exactly what outboard motor to use. I would appreciate advice on this.
   
   
10. Launch wheels
    
    
11. Velixar SonarPhone Transducer - I plan on using this fish finder as it has an android app which can be run on the control computer using software like Anbox. There have been successful attempts at reversing engineering this for Linux but more investigation will be needed to determine whether these still work and are suitable for this system.
    
    
12. Trim tabs
    
    
13. Sofabed - I will make seating that fully reclines allowing it to convert into a bed at night. I am considering making a frame out of fiberglass and wood, using inflatable cushions and a linear actuator to control the movement. There will be storage space underneath. It should be suitable for storing my folding bike
    
    
14. Driver Chair - This will fold down so the bed can extend over it at night.
    
    
15. Rod Holders
    
    
16. Anchor Compartment - A compartment underneath the top deck to store the anchor.
    
    
17. Drinks Compartment - There will be a coolbox in a compartment under the deck. Part of this will be used to store drinks.
    
    
18. Fish Compartment - The other part of the compartment will be used to store fish.
    
    
19. Rear Navigation Light - There will be a 360° light mounted on a 1m pole connected to the transform which can be removed in daylight.
    
    
20. Front Deck - There will be a raised deck covering the area between the helm and the bow.
    
    
21. Storage compartment - There will be a storage compartment underneath the deck. This will contain the coolbox, electronics and charging compartment. The rest of the space will be accessible from a door located on the opposite side (port) to the helm.
    

Next steps
I posted my ideas on here as I would be grateful for some constructive criticism. I want to make it clear that the design presented is more of a concept, that I intend to revise before I start building.


Whilst I wait for feedback on my design, I am going to look for used RIBS/SIBS on EBay, gumtree and on boat forums, as I’m on a tight budget. Once I (hopefully) have some feedback and know exactly what boat I am working with I can refine my plan. I intend to create a more detailed plan on SolidWorks.

 

[Waterwitch]

Sorry, unless the boot of your car is like Dr. Who's Tardis and bigger on the inside than outside your are not going to fit all that gear and a big enough hull in it.

 

[bajansailor]

Welcome to the Forum Adam.

Just one comment - pretty much every item in your Statement of Requirements for this Dr Who boat is absolutely in conflict with most of the other items.
When I started reading this I was sure it must be a wind up - but it looks like you are serious about it, and have obviously given it a lot of thought. Wow.

OK, a second comment. Just go and find a second hand RIB on a trailer and see how much of the kit that you mention can be fitted on it.
At this rate you are going to need something at least 5 - 6 metres long, and costing at least 30 - 50k, not 3 - 5k.

 

[cracked_ribs]

In a sense I'd say there's zero internal conflict within the requirements... maybe a couple of zeros.

But unless the size and budget get an increase by at least an order of magnitude, those are some pretty important zeros.

To build, pure spitball numbers, that looks to me like a ten year build on a fifty or sixty thousand dollar budget.

 

[Mr Efficiency]

Unless Acme Products has a dehydrated boat in the catalogue, this is going to be a tough essay.

 

[clmanges]

Go see this guy:

Q (James Bond) - Wikipedia https://en.wikipedia.org/wiki/Q_(James_Bond)

 

[gonzo]

You should build a plywood dinghy from free plans and get an idea of what boat building is like.

 

[Adam Smalley]

As this is clearly not practical with my budget I have revised the specification to remove most of the more complex parts.

Do you think it is possible to make something I can sleep on with a boat this size or would I need a 5-6 meter RIB?

I have seen examples of people putting tents on small inflatable boats. It does not look very comfortable but it seems that it has been done.

@gonzo that would be a great idea but I want something inflatable.

Specification
It should fit in a car (preferably in the boot).
It should be able to carry a minimum of 4 people, preferably 5.
It should be able to go at least 20 knots with 2 people in. Though ideally I would like to go faster.
It will be used for fishing so if it has an air floor it should have some sort of protection from sharp objects.
It should be seaworthy in F6 winds. I would ideally like it to be able to cross the English channel in good conditions.
It should have nav lights so it can be driven at night.
It should have decorative lights on the floor
It should have powerful enough lights so the deck is fully illuminated at night.
It should have fishing rod holders (at least 5).
It should be modular, to enable parts to be emitted if they are not needed. This is to enable a quicker setup and lighter load for shorter trips.
It should have plenty of storage space.
Should have a waterproof storage compartment for electronics
It should have an anchor
It should run openmarine with pypilot as the autopilot.

 

[bajansailor]

Adam, there is no way that you are going to find an inflatable boat to meet even half of these expectations, while being able to be stuffed into a car boot when deflated.
Even a standard Avon Redcrest dinghy is going to take up a whole car boot when deflated, and it is only about 8 - 9' long.

A boat like this would meet some of your requirements - you just have to accept that you will need to tow it on a trailer.
Fatcat 4000 Multihull, Cardiff - Ad 111166 https://www.findafishingboat.com/fatcat-4000-multihull/ad-111166

Fatcat 4000 — FATCAT 4000 https://www.fatcat4000.co.uk/fatcat4000/introduction

Or how about a Portland Pudgy - but she is not going to plane at 20 knots
Dinghy | Rowboat | Lifeboat | Dinghy Sailboat | Dinghy Motor https://portlandpudgy.com/

 

[gonzo]

As this is clearly not practical with my budget I have revised the specification to remove most of the more complex parts.

Do you think it is possible to make something I can sleep on with a boat this size or would I need a 5-6 meter RIB?

View attachment 164588 View attachment 164590

I have seen examples of people putting tents on small inflatable boats. It does not look very comfortable but it seems that it has been done.

@gonzo that would be a great idea but I want something inflatable.

Specification
It should fit in a car (preferably in the boot).
It should be able to carry a minimum of 4 people, preferably 5.
It should be able to go at least 20 knots with 2 people in. Though ideally I would like to go faster.
It will be used for fishing so if it has an air floor it should have some sort of protection from sharp objects.
It should be seaworthy in F6 winds. I would ideally like it to be able to cross the English channel in good conditions.
It should have nav lights so it can be driven at night.
It should have decorative lights on the floor
It should have powerful enough lights so the deck is fully illuminated at night.
It should have fishing rod holders (at least 5).
It should be modular, to enable parts to be emitted if they are not needed. This is to enable a quicker setup and lighter load for shorter trips.
It should have plenty of storage space.
Should have a waterproof storage compartment for electronics
It should have an anchor
It should run openmarine with pypilot as the autopilot.

The short answer is no. F6 winds generate waves up to 13 feet. Inflatables are not the best for puncture resistance. There are some military and commercial grade boats, but they will be out of your price range. Also, they won't fit in a car.

 

[Adam Smalley]

The reason I am seeking an inflatable that can fit in the boot is that I currently don't drive. I always got by fine with public transport so I never rushed to pass my driving test. I was about to take my test before lockdown but unfortunately (in the UK at least) driving tests are not allowed due to lockdown. To make matters worse this has created a huge backlog.

Fortunately a friend of mine who I fish with has offered to transport the boat till I get a car of my own. However his car can't have a tow bar fitted. Hence why I want something that can does not need to be towed. He has since suggested that it could be carried on the roof rack of the car (deflated) which would allow the boot to be used to carry gear. I am not too fussed about it taking a long time to assemble as when I pass my test I will get a car and a trailer. I also don't have the storage space to store a hard boat so if I went for that option the marina fees would considerably increase the cost.

I'm glad I posted on here rather than blindly setting out to make something that is not possible. Please forgive my ignorance with the proceeding questions:

1) @gonzo I intend to use the boat for inland water ways and inshore fishing. I said I wanted the boat to be usable in F6 winds as I want a boat with an RCD rating of C, as the description of that category matches how I intend to use my boat. I have read that this means the boat can be used with F6 winds. I must be misinformed as I certainly would not want to face a 13 foot wave in a boat that size and I have seen boats for around 1000 and under 4m long that have an RCD rating of C. Please ignore that requirement. Instead the requirement should be just to be seaworthy for inshore fishing on most days. It would be great if I could cross the English channel in it, but that is not important, so this can be omitted if it is not possible within my budget.

2) @bajansailor The size of the RIB I was looking at seems to be the biggest issue. How about these boats:
EXCEL VANGUARD XHD595 | Inflatable Boat. (excel-inflatables.co.uk)
EXCEL VANGUARD XHD705 Inflatable Boat. (excel-inflatables.co.uk)
They are in the size range you said I will need to fit my gear in (from the original requirements), but cost much less than the 50-60k you said I would need to spend. Would either of these boats be suitable or are there factors other than size that make them unsuitable? It looks like it would fit on a roof rack when deflated and bagged up.

By the way I really like the concept of the Portland Pudgy. It seems like a really versatile boat! The problem would be transporting it.

 

[clmanges]

Adam, here's something you might consider. You're going to have to drop some of your requirements, but this will strap to the top of a car and set up easily and holds three people.

NEW 14' (4.28m) Porta-Bote - Porta Bote https://www.porta-bote.com/new-14-4-28m-porta-bote/

 

[bajansailor]

Many moons ago, I was living in England, and I had an Austin Metro and a 10'10" Mirror sailing dinghy - and we used to carry the Mirror on roof bars on the Metro to different sailing locations. And it took up very little space in the yard, propped up against the wall.
Or do you live in an apartment, re how you would not have any space to store a hard dinghy?

 

[Adam Smalley]

I am living with my parents. They will not allow me to store a hard boat. It was hard enough to persuade them to let me store an inflatable...

@clmanges a folding boat could work. How fast would the 14' Porta boat go? It can't take a motor weighing more than 25.5kg. I have had a look at other folding boats. How about this one?
3.7m Adventurer • Quickboats http://quickboats.com/our-boats/3-7m-adventurer/

Are there any other you think I should look at?

@bajansailor What is wrong with the Excel Vanguards?

 

[gonzo]

Porta boats and other folding boats are only adequate for protected waters. They would be category D. As a first boat that would be a reasonable start; particularly since you don't have the place to store a hard boat. However, if you are planning on a trailer, do you have a parking space for it? In that case, the requirement of being a folding boat disappears.