Limit to the first 10 elements of a model in the controller

I'm struggling to understand how promises work in the controller. I'd like to display just the first 10 sortedShips in my template but I can't find a way to get split(0,10) working in my controller.

How can I limit sortedShips or a new property to the first 10 elements only?

app/controllers/index.js

import Ember from 'ember';

export default Ember.Controller.extend({
  shipSort: ['name:asc'],
  sortedShips: Ember.computed.sort('model.ships', 'shipSort').property('model.ships')
});