I believe the overall consensus that you will receive from everyone here will be a resounding NO!!!!!!!!!!!! If you read the reviews of the unit by persons other than dealers who sell them, I believe you can make up your own mind. The fact is that you need a well constructed unit that will stand up to the elements that water hunting throws at a machine. I have not used one but there is a reason for that. I read what others were saying and I knew right away that I did not want to waste my money. The bulk of the good reviews were by folks who use it to hunt fresh water only or use it very little to hunt water at all. The surf and salt water is a whole different ball game!
I would suggest that you do yourself a favor and get that thought out of your mind if you can. A good used American (Garrett) (Whites) (Tesoro) (Fisher) or Australian/(Minelab) unit has a reasonable cost for what you get and will last you a long time and will perform to a level that will keep you from getting discouraged early.
Cobra land machines from the late 1980's and early 1990's were actually pretty good machines. They were made and distributed by a company out of Texas and I even considered becoming a dealer for them, (I have never been a dealer for any company). Their King Cobra machine was really pretty good for its day. I was heavy into coin and relic hunting at the time and I wrote many articles for Western & Eastern Treasures during that time in my life and was at the top of my game back then relative to technology and techniques. I am not sure of the history of what happened but the parent company folded and Kellyco bought the name I believe. Kellyco has always done good by me but saying that, I have to say that I have always bought quality American Made products from them. I purchased White's machines only from Kellycoback when I did business with them regularly. The quality of the Cobra machine offered now is nothing compared to that early land machine. I am pretty sure that they are manufactured overseas. China to be exact on the country.
Think about it long and hard before you make that decision.
Good Luck,
Jim