Mounted the sonar/GPS on a mighty mount on the port side , battery box is in the bow hatch using a water tight connection. , I did use the anchor trolley last Sunday on a test drive , it was great, very windy and it worked well. The hummingbird 581I is "OK" was marking my jig and fish, the GPS was good. This boat is coming along well. On a different note I rolled it on the landing , all was well, I cleared the decks before I hit the beach. Looking forward to.some.fishing lessons.