small pontoon need help (help size pump for propulsion or other shallow propulsion?)

hello iam new here and i need some help if yall could be so kind. iam building a small pontoon 6'x12'. i have it all made up in my cad programs but i need a way to get this thing moving.(motor type) ok so i am making this for dredging in the river's around my house, i plan on using my 4" keene dredge to do the job. iam sick of having to put everything on floats and tie it to a canoe just to get to a good spot so a small pontoon would be great but the issue is in some spots the waters only 5-6" deep so a small outboard wouldnt be a good idea. So i was thinking (never a good thing) would the water pump be able to push this thing? iam not looking for fast speeds but i need it to be able to go against the river about 3-5mph. so is it possible for a pump that puts out 350gpm to do this? here is a link of the pump.http://www.keeneeng.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=P289H&Category_Code=EPif not what well get me to about 10mph? i think the boat will be around 300-400lb. ty for any help.

 

here's a picture of the boat in cad.

 

sorry i dont know jack crap about these things or were to even start to figure out what i need. lets just say i used google alot and ended up here. hope someone can help.

 

Welcome, Gunny.

If the water is too shallow this may inspire you. This is on a frozen lake.:

http://www.youtube.com/watch?v=18g3AJPag9Y

 

i can dig that, i dont even think anyone in the southern states would look at me funny. however i just dont think its safe with my kids and friends going prospecting with me. really i just dont think its safe for anyone in fact i could just see a few beers a dredge and that would make a bad day.

 

Try a paddlewheel between the pontoons. There is also a propulsion system I believe it's called a mud bug or mud something. It is essentially an air cooled engine with a long shaft and a propeller at the end. They use them in the swamps of Louisiana.
My two cents, Mike

 

I have moved 6" diesel water pump mounted on 2- 36" pontoons, 12' long. At idle the discharge hose would push it around a strip mine pit at a speed of 2-3 mph. If you could connect this hose to a tiller mounted discharge pipe you should be able to control it.