As soon as you have complete all of the fishing tasks on your farms, you will get a task and a new ship will dock right next to Oleg on your Flower Farm!
This means that you must have completed all of Oleg's task list first. The last task you need to complete for that particular quest is called "Patience is silver but hooks are golden". Once you have finished that one (buying and using a large minnow hook), the dockyard will be fully unlocked.      Thank you Rowdy Rac

After that step, a new deep sea fishing area will be available to explore!

If nothing works... Check the taskbar on ALL of your farms, looking for any with a fish on the tab & it should be at the top of the list of tasks. Thank you WascallyWabbit

Click on the newFishing icon found on your Farm selection menu ►
or use the Dock yard's ring menu to travel to the Fishing region.

You'll get a new task, "Deep sea fishing".
Omar wants you to buy a new boat so click on the Dockyard.

Only a Motorboat is available until your Dockyard gets upgraded.

Buy the motorboat and you'll see it being built next to the doc. ►

NOTES: You cannot buy a boat while the dockyard is upgrading.
You may have a total of 14 boats in your fleet.
Soon as your Dockyard is upgraded demolish your old fleet for a new better one.