Dude. It's not a race to catch up. Anime is to be enjoyed and watched during your spare time. If your mindset is to "hurry and catch up to the latest episodes" then just stop watching. One Piece will be around for another 7-10 years, so there is no rush to catch up.
Now if you are just dead set on hurrying to catch up, then look up something called "Episode of Nami: Tears of a Navigator and Bonds of Friends". It is a recent anime special that was released summarizing the Arlong Arc into a hour and 45 min episode. A lot is left out, but it is done really well regardless. That should save you some time.
This arc should be watched. It is one of the best arcs in the series and a key point to figuring out of you really want to stick to watching the rest of the series.