Tigre said..
We are interested in information about tide and sea conditions for sailing at Port Lincoln.

Port Lincoln sits on the protected waters of Boston Bay. 15 knots is a typical wind speed during summer afternoons. Re tides, check out www.bom.gov.au/australia/tides/#!/sa-port-lincoln.

The Lincoln Cove Marina (34°44.5'S 135°52.8'E) is a full-service marina, but there are lots of places to drop anchor if you prefer to avoid marinas. I'm told that Memory Cove (34°57.6'S 135°59.5'E), south of Port Lincoln is beautiful.

If you're heading over to Spencer Gulf, don't miss the Sir Josephs Bank Group of islands, a marine park located only a 3-hour sail from Port Lincoln. Reevesby Island (34°31.45'S 136°16.84'E) is the the largest island and offers good shelter from all wind directions. Reevesby Lagoon refers to the semi-protected waters between Reevesby, Lusby, Partney and Marum Islands. Here's a write-up with photos:

blog.arribasail.com/2014/03/cruise-sir-joseph-banks-group.html