15 minutes for 15 metres

  • s15 what is s15?
  • s15 how it works?
  • s15's benefits
  • Software used
  • Glo marine
  • our products
  • General terms & conditions


Designed by a team of naval architects and software developers, S15 is a unique platform providing a fresh and standardised approach to stability assessments of under 15m vessels.

The S15 concept is dedicated to producing the stability documentation for authority approval for fishing and cargo vessels under 15m in just 3 working days, giving you the sought-after control over costs and delivery times. S15’s new approach to stability allows you to save time on paperwork and classic data sharing, via the endless back and forth emails, making the vessel stability aspect, a stress-free topic.

Designed on the Bauhaus principle ‘form follows function’, S15 is created in a minimalistic and intuitive manner to require only 15 minutes of your time and give you full control over the project submission, development and delivery stages.

Curious to find out more? 

Check our demo wizard below.

Not clear enough?

Get in touch with regards to any technical or non-technical query and one of our engineers will reply within 24 hrs.

See us in action.

Click here to have a look at a typical stability booklet generated with S15.

How it Works?

S15 works in 3 stages, all designed to keep you constantly updated with the progress of your project whilst minimising the impact on your daily schedule.

Data acquisition

S15 works in a very intuitive and crisp manner, initially requiring the pertinent vessel data, carefully guiding the user through all topics, making sure that no data is missed so to slow the process. We’ve put a great deal of effort and spent a great deal of time to optimise the data acquisition process so that you save time and only commit to 15 minutes or less to give us all the data we need.


After all data collection steps have been completed and the project submitted, we will take a few hours to ensure that we’ve got all we need and that all makes perfect sense before we approve the project and put all wheels in motion. You will be able to see all these on your Dashboard screen.

If at any point, we realise that some of the inputs do not make sense, we will stop the project, contact you directly to inform you of our findings and proceed only after we know that everything is in perfect order. Thus, saving you the cost and us the time of completing an unnecessary project.

However, if for some reason you mis-read some of the data or perhaps you changed your mind with regards to how much cargo you want on board, we offer one free revision as long as this happens in the first 5 working days after the first project delivery.


Once the input is received and accepted, we will deliver the entire stability documentation for your vessel in 3 (three) days or less. It will all be uploaded on your Dashboard followed by a notification email.

Simple, intuitive and efficient.

Click here to have a look at our demo wizard and familiarise yourself with S15.

Why s15?

At GLO Marine, we know that simplicity is the ultimate form of sophistication, that’s why S15 was designed to ensure that the user interface is crisp and intuitive and the user experience refreshing.


You will only need 15 minutes to complete the S15 wizard. After that, sit back, relax and follow the progress bar.

With S15 you bypass the traditional proposal-contract approach eliminating the downtime and bureaucracy thus focusing on what’s truly important – the vessel.


If during project development or within 5 working days after the first delivery, you decide that some of the vessel’s data has changed and you require an updated stability booklet, we will provide you with new stability documentation at no extra cost.


We did an amazing job at streamlining the workflow such that we can offer this service at a very competitive rate. More than this you will have complete control over your project costs with our fixed rate and no other additional charges.


Once the project is submitted and approved, the stability documentation will be uploaded to your Dashboard in 3 working days or less.

24/7 availability

S15 projects can be created and edited at any time, including weekends.

Subsequent revisions

Subsequent revisions will be charged at 50% of the original price, provided that the hull shape does not change.

Cargo Vessel

Cargo Light

Cargo Light package for the cargo vessel includes the following:

Inclining test report: provided we receive a complete set of inclining test notes we will calculate the lightship weight and centre of gravity and produce the Inclining test report.

Stability booklet for authority review:
- loading conditions for cargo carrying operations – for cargo on deck, cargo in hold and a combination of the two, if applicable.

- loading conditions for lifting operations – for up to two cranes and a combination of cargo on deck and cargo in hold, if applicable. For vessels equipped with two deck cranes, we will look at each crane working independently plus combinations of both cranes working together.

- crane diagram, presenting the maximum allowable moment for each sector.
The stability booklet will also include tank sounding tables, hydrostatics and cross curves for all trim values and allowable KG curves.

Cargo Heavy

Cargo Heavy package includes everything accounted for in the SIMPLE package plus:

- loading conditions for towing operation – for an indicative towing force and two scenarios: vessel subjected to a transverse speed of 5kts and a transverse speed of 65% of the maximum bollard pull.

- loading conditions for anchor handling operations – for an indicative winching load on aft roller.

Fishing Vessel

Light Catch

Light Catch package for the fishing vessel includes the following:

Inclining test report: provided we receive a complete set of inclining test notes we will calculate the lightship weight and centre of gravity and produce the Inclining test report.

Stability booklet for authority review: for fishing loading conditions as per authority requirements plus any special loading conditions that may arise from vessel’s operational profile. The stability booklet will also include tank sounding tables, hydrostatics and cross curves for all trim values and allowable KG curves.

Heavy Catch

Heavy Catch package includes everything accounted for in the SIMPLE package plus damage stability, as requested by some flag authorities for new builds catamarans.

Although we are proficient in using several stability software tools, all documentation issued by S15 is developed using the Autohydro 6.8.0 Pro suite, created by Autoship Systems Corporation.

Autohydro is a complete hydrostatics and stability calculations program for naval architects, ship designers and marine engineers. A true 'floating simulator', Autohydro reports the reaction of the model to various conditions such as a loading configuration, a damage situation, conditions involving outside forces, wind or high speed turning momentum or some combination of these.

Output from Autohydro has been accepted by all major governing bodies such as Lloyds Register, Det Norske Veritas, ABS, Norwegian Maritime Authority, the U.S. Coast Guard and the Canadian Coast Guard.

Who are we?

S15 was imagined and designed by GLO Marine Ltd. after delivering stability documentation for approximately 100 vessels with lengths between 10 and 15m.

GLO Marine Ltd. is an engineering consultancy company located in Surrey, UK, which provides a comprehensive range of engineering and project management services to the maritime industry. GLO Marine Ltd. offers innovative engineering solutions to traditional engineering challenges.

We have a team of 40 engineers across two offices working like a powerful engine, each one bringing a little something to the company’s knowledge and drive.

In 2017 and 2018 alone we delivered the stability documentation for over 100 vessels with lengths of under 15m. This experience gave us the opportunity to notice some patterns and ways of improving the process. Building on that experience we designed and launched S15, an automated platform allowing vessel owners and subcontractors to produce the stability documentation for authority review by spending just 15 minutes of their time, all at a fixed cost.

Our involvement in stability assessments is diverse, ranging from cargo vessels to fishing vessels, oil rigs and small vessels, however our range of services also includes aspects like hydrodynamic analyses, structural design and calculations and subsea engineering.


We’ll save you the trouble of going through the wordy bit of the business and we’ll only focus on the important bits:

Payment mechanism:


Our payments are always processed using Worldpay. Worldpay is a global leader in payments processing technology and solutions, operating reliable and secure proprietary technology platforms.

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Read our full Terms and Conditions here.



S15 is offered as an online service, thus we require payment when placing the project, either using our online payment mechanism or through Bank Transfer directly to our UK account. If the payment is done via Bank Transfer, we will commence work on your project once the funds have reached our account, so this may delay the delivery by one or two working days.

First revision

at no cost

If you accidently provided us with the wrong inputs or if for any reason you are unhappy with the deliverables, we offer one full revision of the entire stability documentation at no extra cost. In order to benefit from this, the request must be made within the first 5 working days after the initial delivery, or during the actual project development.


We can remove the S15 logo and produce the stability documentation with your logo, at no extra cost, if instructed to do so in due time.


The three day delivery term will start once the inputs have been accepted and deemed correct. This refers to business days and will exclude weekends and British Bank Holidays. If the user pauses the projects to update any of the inputs the delivery term will be reset