Hello Everyone and thank you for all your kind words. I am glad you like the Stainless Defender. It has turned out to be a great cannon and I am glad I was able to share it with you all through this fine forum.
The "Archduke" is my gun platform. As many of you have found, the bigger cannons get the harder they are to move. Also, big guns are hard to get to the best places to shoot. Mounting the gun to the bow solved the transportation problem and allows me to bring the gun anywhere there is water.
There are several things I have learned over the years firing over water aside from having to keep things dry. Shooting the gun that is part of the boat is pretty neat. When you are sitting in he drivers seat you are looking down the sight of the Dahlgren. Like a airplane, just point the boat and shoot, steer the craft left or right, trim the bow up or down. The report of the gun is what is all about when shooting over water. It sounds way better than at out the range and truly sounds like rolling thunder. Because of where I am, I have the ability to shoot between or at mountains. When you shoot down a long channel of water you hear the initial boom of the gun and then you hear the sound roll off into the distance. When you shoot at a mountain, you hear the initial report, then the thunder heading toward the mountain at the speed of sound and then the BOOM!!! Sometimes it is hard to believe that you made a boom that big. Another neat thing is that smoke from previous rounds surround the craft making the shock wave visible when the next round goes off.
I would say there are three great things about having a boat mounted gun. First is having the gun when and where you want it. We do a lot of camping on nearby islands Many a time I have looked at a open bay with huge mountains and said to myself "This would be a great place to shoot a big cannon".
Second is the Guns report, cannons sound great over water. When shooting over great distances the act of shooting the cannon seems to last longer. Instead of just a quick boom, you get a boom start, a roll of thunder during and the final crash when the noise hits the mountain or what ever you aimed at.
Third is it is funner for more people. People don't know they like cannons so they do not go to the range. Out on the water everyone is there, family friends, people you don't know.
Logistics of the boat mounted gun.
The very first thing is safety. No "Bugs Bunny" maneuver. You can not flip the gun backwards and shoot your own boat. The barrel can go down and almost vertical but not straight back.
Over water black tape is used over the vent and a rubber NAPA freeze plug goes in the muzzle to keep water out. When you get to your firing location you just walk out on the bow with standard implements and load pre-packaged charges and ignite with fuse. I have used electric but fuse is far simpler.
The barrel is not the far from the water. If there were waves or rough water it could easily drown the barrel. This is ok if you only want to shoot once. As you can see, the Archduke has a landing gear. The Archduke can drive on to the beach, this not only stabilizes the gun platform, it brings the barrel up out of the water. These pictures show the landing gear, the Archduke does not need a trailer to haul. In the final picture you can see me pulling up out of the water on Admiralty Island. Once grounded the craft is stabilized and you can shoot a lot easier and depending on your schedule you can let the whole thing go high and dry.
The Archduke is a semi-submersible I built in 2002, I have probably babbled on long enough about the cannon so I'll post this link to a little article Popular Mechanics did on it.
http://www.popularmechanics.com/technology/engineering/gonzo/diy-submarine-backyard-genius-awardsThank you all for looking and thanks for allowing me to participate in your fine forum.
Here is a video of the Dahlgren underwater
http://www.youtube.com/watch?v=Vpbtxbd_UIM
