According to the Torqeedo website, the Torqeedo 1003 produces static thrust of 68lbs. They also note that "Torqeedo static thrust measurement is based on globally valid ISO standards. Static thrust figures for conventional trolling motors are measured digressively, which results in higher values. In order to compare Torqeedo static thrust data with conventional trolling motors, add approximately 50% to the Torqeedo static thrust values."
So, taking them at their word, the 1003 possibly produces about 100lbs of thrust in comparison with the Mariner's 40lbs that Michael mentions.
After a month using the Torqeedo on my BR20 in the Ionian, where the weather is mostly good and the sea currents negligible, I have come to the following unoriginal conclusions:
1. In any sort of contrary wind, the throttle setting required to stop the bow falling away is so high that the range is severely compromised. So although the 1003 is possibly equivalent to a 3hp petrol outboard as claimed by Torqeedo, this is only true for a short distance, after which and unless you have a spare battery, it is 0hp
2. The whiny noise made by the gearbox even at low revs is grating on the nerves over even short distances. It sounds like a large Kenwood food mixer.
3. The electrical connections, which have to be dismantled at the end of every day for charging and/or discouraging theft, are difficult to screw back together the next day without getting an "E30 error" (faulty connection) message, especially if salty
4. If the boat is used as a taverna taxi, the slow speed (to make sure we can get back without exhausting the battery), whiny noise and general range anxiety give rise to numerous sarcastic comments from my passengers
5. Because the Torqeedo was originally designed for the freshwater Bodensee, I doubt that it would last very long in a strongly saline environment (eg the problem with the thrust washers mentioned in Peter's library article on the Torqeedo)
6. Its plastic propeller is less robust than the steel ones on petrol outboards and easily picks up chips and nicks on its outer edges
7. Given how quickly the battery can be depleted, the time required to recharge with the standard charger (>15 hours) is ludicrous. A faster charger is supposed to be available at extra cost but really ought to be supplied as standard and is still on back order in the UK, nine months after it was first announced
So in future the Torqeedo is only going to be used where petrol outboards are not allowed (Bala, Rutland) and where I want to keep weight down and I know that there are safety boats about (Sail Caledonia). Otherwise like Peter in the update to his library article (about halfway down), it's back to the Mariner 6hp stinkpot with external 20 litre tank for me.
Peter's article can be found at
http://www.swallowyachtsassociation.org/?page_id=820