Anything you can do to either slow down the thieves or inconvenience them is a step in the right direction. If they want it badly enough they'll get it. I've heard a story of a dinghy with outboard stolen off a police dock underneath security. They unbolted the dock cleat and took off with the whole dingy.

1-Be sure to write down the make, model and serial number of your outboard. Take pictures. Etch identifying numbers on different parts of the engine. This is a little bit of closing the barn door after the horse has bolted but this information may help the police identify and retrieve your property.

2-Padlock the transom screws together use a padlock that deters cutting. Or use a transom lock it makes it hard to get the bolt cutters on to the padlock.

3-Make your outboard look not new. Thieves are profit-driven they'll steal that shiny new outboard next to you for a quicker sale. You want your outboard to look unworthy of the risk. Personalize your cowling with the name of your boat or other brandings. Paint the cowling a bright or ugly color, make it unattractive for resale. If you are concerned about resale buy a cheap beat-up looking cowling for your motor off of eBay or other online spots and store your spiffy cowling to put back on when you decide to sell.

4-If your boat is on a trailer back up to a solid wall. Not a chain-link fence if it can be cut from the other side. However, chain-link does have the advantage of the thief being visible. Back it up close to make it harder to get at and maneuver it away from your boat to the thief's vehicle.

5-Get to know your neighbors. It's easier to spot strangers if you know each other. If they know who should be around your boat and who shouldn't be they might ask questions. Or be able to identify the thief.