I am about to start a course for boating license for boats up to 40 gross tons. I wonder how big such a boat is?

I looked everywhere for concrete examples, but most only provide length or other metrics.

Is such a boat huge? Is it like a motor boat in tourist areas for 4-5 people?

  • 1
    Imagine a 40-ton container on a semi trailer. Compare that with a motor boat for 5 people. Nov 11, 2022 at 23:59
  • @WeatherVane thanks, that makes sense! So its fairly large. Maybe even up to 10 people depending on boat? Nov 12, 2022 at 2:02
  • 1
    @PMF, yes - I assumed that was understood. I was observing that they tend to be much bigger than your typical recreational yacht. In fact, I happen to live quite near to where the Ninian Central oil storage platform was built - 600,000 tonnes of concrete, and the world's largest movable object at the time. Nov 12, 2022 at 18:11
  • 1
    @DaveX my license is Bulgarian internationally recognized not sure if it has a person limit as far as I know it doesn’t only boat size. Nov 16, 2022 at 14:41

2 Answers 2


A boat of 40 gross registered tonnes is a substantial vessel.

For example here is a link to a vessel for sale of 48 GRT. It's a "passenger carrying boat used in tourist areas" like the ones you are asking about. This one is sixty foot long and carries 95 passengers.

  • Passengers vessels may be rather flat bottomed and having an angular cross section, with very little space for anything but passenger seats. Yachts stick quite often much deeper, with space for bed(s) and more space per seat, as well as space which is not useful or used for storage of water and such. If the license only gives gross tonnage as limit you have to compare with the boat you expect to use, not with a different kind of vessel.
    – Willeke
    Nov 13, 2022 at 11:36
  • The OP asks about passenger-carrying tourist boats. Nov 13, 2022 at 14:09
  • A motor boat for 4 - 5 people sounds like a yacht to me, not like a many people capable tourist boat.
    – Willeke
    Nov 13, 2022 at 15:34
  • "Yacht" can mean a lot of different things, from small sailboat to giant luxury cruiser. Nov 13, 2022 at 20:08
  • Thanks Anton or even 40! Now I feel more motivated about the 100h of theory awaiting me. Nov 16, 2022 at 14:38

Having used google to get a feel, I found a Wikipedia page about Gross tonnage as well as several tonnage calculators which will help you work out to get the tonnage of a given boat.

I entered a few random sizes (as I am not a boat person the length may not be right for the width and depth, but these are which I used to get near 40,) length 40 feet, width 6 feet and depth 8 feet, and it came to 38.4 gross tonnage. Find the sizes of a boat you would consider sailing and enter them, and see how they work out compared to the limit of 40.

I linked to the first calculator which did not insist on spam, no affiliation.

  • I don't know who came up with that calculator, but it's got some huge flaws. For example I have a sailboat with a displacement of around half a tonne, and a gross tonnage of not much more. If I enter the figures it tells me the tonnage is 3 tonnes. If I entered it's actual keel depth it tells me it's more than ten tonnes. Nov 13, 2022 at 14:21
  • @DJClayworth, boats come in many different shapes and the calculator will likely only give good answers to one shape, yachts with a keel are likely not the basic they work on. I guess it will be more for freight boats, seeing your reaction.
    – Willeke
    Nov 13, 2022 at 19:14
  • I also fed in the figures for the example boat in my answer and it calculates the GRT to be more than twice what it really is. Nov 14, 2022 at 2:36

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