Double Trouble on Vacation by Michael J. Pellowski, 1989.
The Daniels twins are at it again! Sandi and Randi are looking forward to spending their vacation at the lake with their family. Sandi is trying to work on her wilderness merit badge, and Randi just wants to go fishing. But, when Bobbi Joy, a bully they know from school, turns up at the lake, visiting her cousin, the girls make the mistake of accepting a bet from her. Randi bets Bobbi Joy that she can beat her in the fishing derby, not knowing that Bobbi Joy’s cousin, who is her fishing partner, is a fishing champion. Although the stakes are fairly harmless, just taking a jump in the lake with all her clothes on, Randi still can’t stand the idea of losing to Bobbi Joy.
Things get complicated when Randi is sprayed by the skunk that their little brother Teddy tried to befriend. Randi doesn’t want her team to be disqualified from the fishing derby, but she can’t go smelling like skunk! Instead, she talks Sandi into taking her place once again. But, Sandi has to give a speech later that day in order to get her merit badge. Can she help her sister and still make it in time to make her speech?
This is the last of the four books I have in this series, but there are two other books in the series that I don’t have and haven’t read: A Double Trouble Dream Date and Double Trouble Mystery Mansion. In A Double Trouble Dream Date, the twins conspire to get roles in a new music video with a teen star, when only Sandi is actually able to sing. In Double Trouble Mystery Mansion, the girls are investigating a haunted house which holds a hidden treasure. There is a real ghost in the story, but only Sandi has been able to see it. At first, Randi doesn’t believe her that there even is a ghost, and the girls attempt another switch to see if they can convince the ghost to show himself to Randi, too.