We like two dinghies. One large 11 1/2 to 13 feet with 15 to 25 hp and a second with 3 to 5 hp--either a light weight inflatable or light weight hard dinghy. The bigger boat is for longer trips--and there have been places we have gone as far as 30 miles in the RIB. It carries more capacity and is really seaworthy--having rescued people in a swamped Boston Whaler. The lighter and small dinghy can be carried up on a beach or taken thru surf--something you will not want to consider with the larger dingihy. However do consider the large pneumatic wheels for a dinghy--we use 12"--the small plastic ones are not satisfactory. As for security--bring it aboard each night--have a good system to do this so it is easy. We have had one stolen with the cable/chain not being of any value--the towing eye cut out of the NEW boat and motor--about a 5 K loss. As for attatchment of the cable/chain--an eye bolt in the transom, with the head peened over well , is as good as you can go--consider hardened chain/plus cable. Bob Austin