I've been running Trigger Maru (latest version 1.6.5) for awhile now & have completed patrols based out of Cavite, Surabaya & Fremantle before tranferring to Pearl & upgrading to a Gato. The program so far has run touble free. However on one patrol out of Pearl I decided to have a look around Truk Island whilest on the way. On approaches from the north then from the south I found that when in the shallow water section of the lagoon, my compass started to deviated from plotted course & the boat refused to go in the direction I wanted it to. It either stopped completely (the submerged depth under keel was still sufficient -10 feet to avoid running aground) or would veer off in a east/west direction. I couldn't even go astern to return to my orginal approach position. To get out of the situation I had to reload my last saved position. On repeating the same thing the abnormality occurred again when I tried a different approach. So far this has only happened around Truk Island.
Has anybody also experienced similar situations?