Custom built Los Angeles Class 688i fast attack submarine. This is my forth generation of submarine models and the pinnacle of 13 years development and experimentation. Each generation has gone though an evolutionary process of improvement, the end result being a submarine model that is virtually unsinkable. Fast on the surface and even faster submerged, this submarine will always resurface on its own even if radio contact is lost. The only exception is if you have the unfortunate experience of plunging into lake bottom mud at full speed . . . but a careful captain need not encounter that particular situation! The key to repeated successful voyages is to watch your speed, always maintain visual contact and never dive deep enough to lose sight of your submarine. The model is 43.75 inches long with a four-inch beam, and is 6 - 3/4 inches from the keel to the top of the sail tower. The hull, bow, stern and hatches are molded epoxy with fiberglass reinforcement. The smaller parts are made with epoxy castings. This hull is heavily built up with three distinct layers of fiberglass cloth, each layer of cloth is soaked in epoxy and when the cure has set another layer of epoxy is applied before the next layer of cloth is put in. The heavy-duty nature of this buildup is required because this is a pressure hull. This submarine model requires the hull to be hermetically sealed and able to hold the internal pressure of compressed air. This is a radio controlled submarine that takes on ballast water to submerge, using a snorkel venting system for the main ballast tank set up to automatically surface the submarine model when the transmitter sticks are set to neutral (center positions). An extensive set of technical and test tank videos are available on my "coolmodelguy" YouTube Channel. Copy and paste this URL into your browser: https://www.youtube.com/channel/UCJcwba_XNNvf6eIlwkv2miQ Click on the "Videos" link on my YouTube Channel page.