Thanks for the suggestion, I tried this in creative mode but anchor only fixes the position within a certain range and thats it.
Tried this out with one sail, two sails, no anchors, two anchors, all kinds of angles and combined with paddling while swimming towards the raft.. nothing really works, this is a really basic and important issue, Its frustrating to keep missing most of the items in the normal mode until I find a raft or an Island to crash into..
This is the only Issue Ive had in the game.. oh well.