Before you start practicing this knot, review the steps for tying the regular Bowline Loop. Once you learn the Bowline, this knot is quick and easy to remember.
1 Start as you would to tie a regular Bowline, then use the running end to make a second loop.
2 Continue the same as you would with a Bowline.
3 Finish by making the final tuck.
With the Portuguese Bowline, you'll have two loops that can be adjusted in relative size after the loop is tied, but the strain on both must be equal.