1.5 - 2 knots for live bait trolling!!! I need an auxiliary engine for that. My engine just engaged into forward already makes 3.3 knots on average!
Thanks for the replies
That's what trolling valves are for on the bigger diesel engines

Otherwise another option is to add drag with a drogue but its not very fuel efficient.
On the other hand you should have a nice trolling speed of 6-7 knots for Albacore, Tuna etc