Title of next episode of Naruto Shippuden 231 is "The closed Route".
Tsunade is counting on Shikamaru to lead the Hidden Leaf to war. Sitting on a porch Shikamaru confesses to his dad that he has doubts. Shikaku suggests that he keeps his eye on the ball and go see Naruto. Taking a supply mission may be a nice diversion for Shikamaru. Shikamaru with Tenten went to Mokuzu Island to get supplies. Then boarded Naruto ship. Shikamaru asked about Guy sensei. Happy and no longer sea sick Guy sprung from his cabin. Fog is very thick and no one can see a thing. From the water rocks sprung out and Naruto ship hit one of them so hard that both Guy sensei and Naruto were thrown over board. They would have fallen into the water, but Shikamaru with his quick reactions and Shadow Strangle Jutsu saved them.
There were not supposed to be reef structures in these waters. Guy sensei started jumping fro one rock to the next breaking them to clear the way for the ship. Huge rock appeared out of nowhere. Guy jumped but unable to break it. Yamato had to use his Wooden Jutsu to wrap around the rock to then steer out of the way and missed it by a hair. 
A huge whirlpool appeared. Rudder stopped working and whirlpool kept puling them in. Shikamaru suggest hitting it hard with massive Rasengan. Naruto blasts the whirlpool right off and Yamato pulls him back on the ship. Thinking they may all be saved, all of this started repeating. Shikamaru was reminded of a Shobi board game he played with his father and how Repetition got him to lose his game. Here in these waters it all looked like someone was trying to abduct Naruto, or at least have Naruto, Yamato and Guy to loose all their chakra.
No enemy was sensed, no transportation jutsu or genjutsu used. 
Shikamaru realized he was the only one still with chakra left. Naruto grabbed him by the shoulder however and told him to use his head to get them out of there. Naruto the called for a clone jutsu and pulverized all rocks with his clones. Shikamaru taking this time to review everything that happened to them from the moment they left the port, realized that this day was a spring tide day. Could this be a natural phenomenon?
Right the a huge rock appeared and Shikamaru noticed a glare of sort. Then he noticed a marking on a side of the ship. He figured the ship must have been going around a circle time and time again. When another whirlpool showed up and Naruto was out of chakra, Shikamaru suggested that they sail right through it.
Bandit gang trapped the ship by Devil's Water Trap. When they all surrounded the whirlpool wanting to snatch all the shinobi treasure, they were caught by a surprise as all shinobi stood on the water and Tenten threw the ship up at these bandits.
BBQ is reopening. Tenten made her reservation already. It seems like we're going to witness one heck of a ladies night out in the next episode of Naruto Shippuden 232 . It will come out on Thursday and it will be entitled "The Girls' Get-Together".