Question about and backstory of Navacal.com

[Robert-Shetland]

I’ve been posting here recently about Navacal.com which i created, but there’s a bit of background story to it.

Over the past few years, I went back to basics and taught myself small boat design and naval architecture properly through distance learning courses, online resources and books, and a lot of work improving my own designs, i learned naval architecture as part of my marine engineering qualification but after so long most of it was basically relearning, so i started from the basics and learned it from the ground up so to speak.

That led to restarting our company RL Marine and building a 23ft demonstrator boat, which I’m currently working on (current progress photos attached along with a render of what i will look like when complete).

When it came to proving compliance and certifying the boat for sale with the EU Recreational Craft Directive and the new UK regulations post-Brexit, I tried existing software for scantlings and stability but for one there wasn't a program available which could do both in one platform and not only that but i thought it would be ideal to be able to compare the design between various scantling standards / rules without changing programs, I have Orca 3d which is great and can do the hydrostatics and stability checks but can't do the scantling part, I then decided to try and make a program which could do both these things along with many others and make it as user friendly as possible. This is where the learning started again, this time computer coding with Python and other programming languages and i built what is now Navacal.com.

Navacal has only been live since December 2025, but the aim of the program is to make boat structural and stability calculations more efficient, easier to complete, and more accessible for designers and builders worldwide and from reviews from users so far i believe Navacal.com will do just that.

there is a free 30 day trial of the program available, so please sign up if you are interested or please ask if you want to know any more about it.

Something i would like to ask the community on here is, what do you think of the program, the idea its self and the implementation, anything anyone could see that could be added or improved, or anything i could add to make it more useful to anyone, any suggestions are welcome and happy to discuss anything that would make people's design / calculation flows easier.

 

[Ad Hoc]

... what do you think of the program,...

Hi Robert,

I admire your tenacity in writing such software.
But, in my opinion, it is most likely doomed from the start….why?

1. No professional naval arch would buy it. Why??... because they either already have something in-house anyway, or like most when dealing with Class, say LR, you either get their SSC software rules for free with a contract with LR, or, you can pay them £250 (if no contract) I think it is, from memory. All done, simple and straight from the source. Other Class societies do similar too. Some are free now I think too.
Thus no processional has a need for such a bit of software, they have it covered.

2. This takes you to amateurs.
Most amateurs, only want a “check” on what they “think” will work, against what would work, in the absence of being able to calculate it themselves. Most amateurs lack the knowledge of the rules and the background for structural engineering/design. Thus this type of program is aimed here.
So, as such the fees you charge are beyond what 99% of most amateurs would be willing to pay for, to get answers. Most would come onto a forum like this and seek answers, and assistance for free.
Waiting a day or two to get a reply that satisfies their needs, is a lot better than paying a large sum for a program being used only a few times, at best.

If however you had it say £50/year and monthly subscription of £5/month, aaahh….then it falls into the not much more than a round of drinks down the pub. This then becomes justifiable, and would open up your potential base from 1% to around 50% or more. I would remove the network licence, for the reasons outlined above.

My 2/c worth.

 

[Robert-Shetland]

Hi Robert,

I admire your tenacity in writing such software.
But, in my opinion, it is most likely doomed from the start….why?

1. No professional naval arch would buy it. Why??... because they either already have something in-house anyway, or like most when dealing with Class, say LR, you either get their SSC software rules for free with a contract with LR, or, you can pay them £250 (if no contract) I think it is, from memory. All done, simple and straight from the source. Other Class societies do similar too. Some are free now I think too.
Thus no processional has a need for such a bit of software, they have it covered.

2. This takes you to amateurs.
Most amateurs, only want a “check” on what they “think” will work, against what would work, in the absence of being able to calculate it themselves. Most amateurs lack the knowledge of the rules and the background for structural engineering/design. Thus this type of program is aimed here.
So, as such the fees you charge are beyond what 99% of most amateurs would be willing to pay for, to get answers. Most would come onto a forum like this and seek answers, and assistance for free.
Waiting a day or two to get a reply that satisfies their needs, is a lot better than paying a large sum for a program being used only a few times, at best.

If however you had it say £50/year and monthly subscription of £5/month, aaahh….then it falls into the not much more than a round of drinks down the pub. This then becomes justifiable, and would open up your potential base from 1% to around 50% or more. I would remove the network licence, for the reasons outlined above.

My 2/c worth.

Hi Ad Hoc,

Thank you for your reply, I appreciate you taking the time and I’ve taken all your comments onboard.

I fully understand how difficult it is to break into this space or any space where existing methods of doing something are already in use and thought to be the "best way" of doing it. Many people / companies already have their own tools (Excel or similar) or use existing software, and / or use class specific ones as and when required, and are used to & happy with their existing workflows and processes. That said, from the feedback I’ve received so far from several Naval Architects who are now using it regularly, the biggest benefit they have fed back is the significant time saving on calculations and optimising designs for weight / strength. Some of the users fed back to me that some projects that used to take up to several days with spreadsheets or multiple programs are now being completed in a several hours, with much faster iteration and optimisation of designs. Where time = money as with any business, the potential of a significant time saving should be of benefit to any company doing this type of work with similar existing methods.

The main reason I added Lloyd’s and BV rules alongside ISO was to make it simple, just change a dropdown to calculate the same design against multiple standards, all within one program. You can calculate scantlings, other structural elements (welding, rudders, keels, engine foundations, propellers, thrusters etc), and full ISO stability assessments (12217-1/2/3 and 6185) using a 3D STEP model. It’s also designed for easy collaboration where users can share design files across team members, using any device whether that be a PC, Tablet from any location on any device with an internet connection.

A particularly useful feature which has been mentioned by several of the current users for optimisation is the ability to instantly change stiffener sizes, laminate layups, materials etc and re-run calculations with just a couple of clicks. This lets you quickly optimise weight and strength in real time against the 3 standards.

I think / believe many people currently using spreadsheets or separate tools would find Navacal a big productivity boost once they try it. The 30 day free trial is available and I hope that people will give it a try so to speak and sign up for the free trial, nothing to lose if doing this type of work regularly, and if it can help improve the workflow and make your workflow more efficient then why not give it a try, some will like it and find it an improvement, and some wont which is the same with everything in use, but for many I’m confident it will be an improvement and increase their efficiency and productivity.

On pricing, I’ve been thinking about this recently. I’m considering a tiered monthly subscription model to make it more accessible to users with various use cases, something like the following tiers keeping the full suite at the 50 month / 500 year full package price.

ISO scantlings only
ISO scantlings + text-based calculators
Full LR, BV, and ISO scantlings + calculators
£50/month — The complete package (including 3D STEP model import and processing for mono- and multihull stability assessments, plus all BV/LR calculators)

I’m still thinking about the pricing for the lower tiers, but the top tier currently at 50 pounds a month is already (without future additions) equivalent in capability to another commercial scantling + stability package which is ISO only.
Navacal as a webapp with no high initial investment is significantly cheaper over a 10 year period. As an example if using Navacal for 10 years it would be 5000 pounds if on the yearly subscription. If a user purchased other available software with all modules included to be equivalent to Navacal it would be over 9000 pounds and locked to one PC, so with that comparison i dont think the full version of Navacal is overly expensive especially with the additioinal Lloyds and BV calculations but the lower tiers im looking into may help users who dont need the full package to use what they require only.

The network licence option, this was added after discussing it with a user who runs a naval architecture company. I’ve had similar interest from another company who also asked about adding ABS rules for the US/EU market so they could produce reports for both standards / rule sets from one program and I’m currently working on adding the ABS scantling module.

I would be interested to hear your thoughts on the above, and if you have the time please feel free to sign up to the 30 day free trial, i would really appreciated having your feedback on it after using it.

Best regards,
Robert

 

[Ad Hoc]

Robert,

So, how many users do you have who have purchased your software?

 

[Robert-Shetland]

Robert,

So, how many users do you have who have purchased your software?

There are currently 12 active users, including a few Student licences which I agreed with three universities that asked to use it as part of modules for naval architecture courses. Hoping to have some reviews from some of the users soon which i will post on here and on the review section of the website.

 

[Ad Hoc]

There are currently 12 active users, including a few Student licences ....

So other than those students with their licences, are the others professional naval architects, or amateurs, or other?

 

[Robert-Shetland]

So other than those students with their licences, are the others professional naval architects, or amateurs, or other?

All others are Naval Architects

 

[Ad Hoc]

So, question to you....how many more users are you aiming to get?, or is that not the metric?

 

[Robert-Shetland]

So, question to you....how many more users are you aiming to get?, or is that not the metric?

I wouldn't say i have an aim for X amount of users, I've made it and think its a good program and hope it will be helpful to people doing this type of work.

 

[Ad Hoc]

I wouldn't say i have an aim for X amount of users, I've made it and think its a good program and hope it will be helpful to people doing this type of work.

That's why I am saying reduce the price as I note above.
And then your user base will grow and you'll find more amateurs willing to part for a round of drinks.

Otherwise, I don't see what you're offering is any different from what is already out there, sometimes for free, to those that feel the need for such a program.

 

[KND]

Hi Robert,

I admire your tenacity in writing such software.
But, in my opinion, it is most likely doomed from the start….why?

1. No professional naval arch would buy it. Why??... because they either already have something in-house anyway, or like most when dealing with Class, say LR, you either get their SSC software rules for free with a contract with LR, or, you can pay them £250 (if no contract) I think it is, from memory. All done, simple and straight from the source. Other Class societies do similar too. Some are free now I think too.
Thus no processional has a need for such a bit of software, they have it covered.

2. This takes you to amateurs.
Most amateurs, only want a “check” on what they “think” will work, against what would work, in the absence of being able to calculate it themselves. Most amateurs lack the knowledge of the rules and the background for structural engineering/design. Thus this type of program is aimed here.
So, as such the fees you charge are beyond what 99% of most amateurs would be willing to pay for, to get answers. Most would come onto a forum like this and seek answers, and assistance for free.
Waiting a day or two to get a reply that satisfies their needs, is a lot better than paying a large sum for a program being used only a few times, at best.

If however you had it say £50/year and monthly subscription of £5/month, aaahh….then it falls into the not much more than a round of drinks down the pub. This then becomes justifiable, and would open up your potential base from 1% to around 50% or more. I would remove the network licence, for the reasons outlined above.

My 2/c worth.

I agree partly with Ad Hoc, but I think Navacal’s value is in the wrong place in this discussion.

It is not a replacement for class software. It fills the gap before that stage.

In a professional office, we spend a lot of time on concept design, tenders, and proposals. At that stage, class software is often too slow and too heavy for quick feasibility work. Navacal is valuable because it gives fast, reasonably accurate scantling and rule-based checks early on.

For us, the big advantage is having several rules in one place, plus quick tools for items like girder checks, windows, speed, and propeller assumptions. That makes it very useful for early-stage design decisions.

In tender work, where success rates can be low, you cannot spend full class-level effort on every opportunity. You need a fast technical snapshot within hours. That is where software like Navacal has real value.

Once the project is secured and moves into class, then of course we use the official class route. But by then Navacal has already done its job well.

Well done to Robert. For me, this is a very useful software to have in a naval architect’s pocket.

 

[Ad Hoc]

....In tender work, where success rates can be low, you cannot spend full class-level effort on every opportunity. You need a fast technical snapshot within hours. That is where software like Navacal has real value.....

I think that is where experience come into this debate.

I have a range of simple excel spreadsheets, (ABS, DNV etc), with the primary structure requirements, I've created over the years.
In essence I do exactly what you're referring to, in about 5mins.

In addition, when designing vessels which are "similar" i know from previous vessels what will and wont pass.
Thus often removing the need for any checks in that sense.

So, if you have a limited database, then perhaps yes....some may find this of value, in that sense....but with time and more experience, not so.

 

[TANSL]

Good work, Robert, keep going down this path. Your competitors aren't just simple spreadsheets, which can only offer very limited solutions. No one should dismiss a new tool without having the necessary resources, experience, or knowledge to analyze it.
Congratulations on what you've done so far, and keep your spirits up because the road ahead is long, though very rewarding. Not everyone, even n.a. with huge databases, is equipped to do this. Sowing doubt, into others woork, is much easier.