Hey Guys,
Hmmm,.... anchors,.. one of my least favorite toon accessories. I have used a number of different anchor systems in the past with limited results. The tried and true cement cylinder (a' la every rental boat in the universe), is the simplest and cheapest.
Advantages:
1) cheap
Disadvantages:
1) bulky,... take up a lot of room and are not always easy to deploy, because of their size
2) doesn't hold well,... there is a whole list of reasons why, like,.. the cylindrical shape, the relative low density of concrete, the lack of flukes,... etc., etc.,....
By the way 10lbs. is probably sufficient, if you can make the sucker stick! Besides you probably don't want to carry much more weight than that.
The next issues are
where to tie the thing off
managing the line
hauling
Most of the pontoon manufacturers have add on accessories for anchoring their boats. Check out the sites and you can get a good idea of what you might want. The best anchor I used was an 8lb galvanized unit that resembled a plow share. Sank very fast, usually stuck fast with little effort, and for the sand, gravel and small rock bottom we were fishing, worked really well. Another good one was the bell, (inverted mushroom) and/or the scalloped bell. Again 8-10lbs.
as far as anchoring in the rocks?,... well it's risky no matter what the anchor.
For the most part I have so rarely need or wanted an anchor I no longer have one. But I usually fish still water. If I start bay fishing I may rethink this.
hope this helps
bodfish