I've looked for similar questions as How to write the “plural of plural”?, but my question might be slightly different.

There are boats, and each boat may have zero to many engines. Which is more correct to say:

  • Boat Engines
  • Boats' Engines
  • Or else?

And then what if there are manufacturing companies:

  • Company Boat Engines
  • Companies' Boat's Engines
  • Or else?


Since it depends on context, I'm actually using these for I.T. purposes, as in function names and database table names, etc. While there are powerboats, there are also traditional boats (zero engines). In the database, there are cars and car engines, bikes and bike engines, etc. So if I want to refer to the boat engines, I need to specify the type (cars or boats or else).

  • 1
    Company Boat Engines eminently serves the purpose, provided no conflicts in context. Any objections?
    – Kris
    Apr 9, 2017 at 14:53
  • Describing the engines themselves and replacing 'Company' with the actual company's name? No objections if we're talking generic phrasing, but actual companies call them marine engines.
    – lly
    Apr 9, 2017 at 15:09
  • Provide sufficient context so as to be able to omit boats before engines. Apr 10, 2017 at 4:29
  • @Kris I think you have the clearest idea, please post an answer.
    – evilReiko
    Apr 10, 2017 at 10:02
  • 1
    I stumbled across this post also while searching IT variable naming purposes. I've settled with boats_engines, in order to doubly convey a plurality going on there so that it's not accidentally mistaken for: boat's engine, boat engines
    – gunit
    Nov 7, 2017 at 19:21

2 Answers 2


It honestly depends on what is the focus of your sentence and how you'd like to convey your ideas.

If you want to talk about the company's engines as separate from the boats (i.e. if you were to take the engines out of any specific boat, place them on a pedestal, and talk about them), you would use the following:

The company's boat engines are well-designed and durable.

Here, the focus is on the company owning "boat engines"--that is, engines specifically designed for boats.

If, on the other hand, you'd like to talk about the the engines in relation to the boats (i.e. perhaps an engine that has already been installed in a boat), then you'd say:

The company boats' engines are well-designed and durable.

Here, "company" serves as an identifier for what type of boat you're discussing (a company boat, as opposed to, say, a private boat). In contrast with the first sentence, the boats--not the company--now more directly possess the engines.

Perhaps the least ambiguous of them all would be the following:

The boat company's engines are well-designed and durable.

With this revision, you no longer have to worry about plurality, and it's clear that: 1) the company handles boats and that 2) the engines are specifically designed for boats.

If you'd like to pluralize "company", then it's a trivial revision:

Boat companies' engines are [insert information here]

  • This doesn't seem to have anything to do with the question, which was about the phrasing for multiple engines of multiple boats.
    – lly
    Apr 9, 2017 at 15:12
  • Well, each sentence in my post implies plurality for both the boats and the engines. The very last revision addresses the concern of pluralizing the companies.
    – AleksandrH
    Apr 9, 2017 at 15:13
  • The company boats' engines are well-designed and durable is ambiguous as to whether the boats have single or multiple engines. Afaict, Reiko was asking how to unambiguously state that multiple boats had multiple engines in a straightforward way, without the possibility that multiple boats' single engines were intended.
    – lly
    Apr 9, 2017 at 15:17

There isn't a straightforward way to express what you want to say and you'd have to clarify, just like you did in your question.

The four engines on each of the several boats...

The numerous engines of each boat...

Each boat's handful of engines...

There are a few boats, some unpowered and others with many engines.

(A zero-engine powerboat isn't really a thing. One is the minimum.)

The companies would probably use latinate and commercial phrasing to sound more professional: marine propulsion, marine engines and systems, &c.

Edit: Depending on what you're trying to say, there's multiple-engine boats and boats' multiple engines, which would exclude the possibility that the boats' engines were on numerous single-engine vessels.

  • 1
    Rephrasing is not an answer, though.
    – Kris
    Apr 9, 2017 at 14:52
  • Reread it. There's a reason the rephrasing is necessary.
    – lly
    Apr 9, 2017 at 15:11
  • 1
    Even so, what we need is an answer.
    – Kris
    Apr 9, 2017 at 15:13
  • Which was given. Keep at it. You'll see it.
    – lly
    Apr 9, 2017 at 15:14

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