Know your Nautical Terminology
reef
Rock or coral that is either partially submerged or fully submerged but shallow enough that a vessel with a sufficient draft may touch or run aground.
reef-points
Lengths of rope attached to a sail and used to tie up the part of a sail that is taken out of use when reefed. In older systems, such as square or gaff rigs, the reef points take some of the load on the sail and distribute it to the boltrope; with slab reefing, the reef-points just keep the sail fabric controlled in a tidy manner. Reef points may either be sewn to each side of the sail or passed through eyelets.
"Reefing" sails was a way to take in some canvas when high winds would put too much strain on the the sails. With the upper boom lowered slightly, canvas was gathered in and the reefing points on either side of the sail would be tied around the lower boom, and secured with a "reef knot" (also called a "square knot"). With the reef points secured all along the boom, the sail would present less area to the strong wind, which in turn put less strain on the ship's rigging. You will notice that the sails shown in the painting have two sets of reefing points. If sail is taken all the way to the second set of reefing points, the sail would be "double reefed". 
WWG1WGA
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)