A boat and riding lawnmower have been added to the string of trailer thefts that have plagued the county the past two weeks.The two most recent thefts follow the same mode of operation in that the thief pulls up to the item, hitches it to his own vehicle, then drives away.“We’ve really seen an upsurge in trailer thefts the last few weeks,” said sheriff’s department investigator Marc Martin. “It’s hard to say if all of them are the same person, but I’m sure some of them are the same person.”A bass tracker boat was stolen from the driveway of a home on Lowery Lane on Thursday, the same day a lawnmower and trailer were stolen from a home off Old Shelbyville Road.Martin says trailer thefts traditionally soar in the summer for two reasons. First, people need trailers to pull lawnmowers, four-wheelers and other items that are used more often during warm weather.Second, people using their trailers frequently may not be careful to secure them after every use.