The angle of deflection of the motor now we can setting the bigest is 90.but i thank should be 180！
Usually ，out motor of the boat been installed at the end of boat，and the angle of the FC same with boat ！so the biggest angle of deflection just 90 °，if not， the boat will countermarch ！
I agree the angle limit at this condition.
BUT！！！！IF the Motor install at the front of baot，and the fc can turn with the motor！AND biggest angle can be 180°
WHAT WILL HAPPENED???
the boat turn arond will fast ！ why we need FAST？
that is key point of the article ！ Loiter mode
now we can imagine the boat float down the stream， we use theloiter mode， bcs the the angle limit of 90°，the boat need to move and turn aroud。 BUT we put fc same condition with motor， when we use loiter mode， motor will trun to 180° and fc same， now the motor just need to start ， the boat will stay at the same place， needont move a semicycle。and about the stream ， the stern will turn 180°，but the boat still at the same place to finish the order of LOITER MODE！
that is how the GPS Anchor work！ so ， it will can be used for real boat, fishing.!
In the end, sorry about my english, bcs i dont speak english. but i hope us can read all !
AP Boat doesn’t yet support turning a motor around 180deg to backup instead it assumes that a motor can spin backward. This has been requested a few times actually so we will probably add support eventually.
There’s a LOIT_TYPE parameter that allows specifying if the vehicle should always move forward to the target location or whether it is OK to move forward or backwards.
about the LOITER MODE，my idea is add another choice，
the fc just need to stay at the same place，need dont lock its orientation， then the boat will spin by the ocean current，at this mode， the motor always pull the boat to stay，not push， it will save a lot of power，
about the vectored thrust， if it can set 180°，when the boat downstream ，just need to let the motor turn around, if for 90 ° ，the boat need to move then go back the Original position。maybe some one 90 some one need 180 。but i think it can be a choose ,it is better.
I also support this idea. I made a RC-model of a tugboat with ASD(Azimuthing Stern Drive), 180° would be very useful(360° ideal ). Ideally, it would be possible to get a similarity of the DP system.
). Ideally, it would be possible to get a similarity of the DP system.