Chip, Yes. All things being equal a 25lb anchor
will be better holding than a 16lb. The main reason is that the effective fluke area of the 25lb anchor will be larger than the 16lb. So for the exact same conditions the 25lb will have more surface area, thus resistance to dragging and holding the boat. The secondary reason that the 25lb will be better is that it is heavier and thus will be able to get down into the seabed to set quicker and deeper.Thats why (once they set well) you see these lightweight fortress/danforth anchors having more resistance/holding power in straight line anchoring tests than much heavier traditional anchors such as a CQR or others. But the real problem with those lightweight anchors is that they down't always set right away or well because they are so light, sometimes (due to water current or other reasons) they just "skate" away from the boat or along the bottom and don't immediately "dig in" Thus the need for the extra chain sometime to really pull the shank down and help set the anchor.Here is a nice informative site (albeit a bit biased due to the anchor it promotes). But I do truly beleive that it highlights very important apects in what is required of a good anchor.http://www.spade-anchor.com/Site%20anglais/US/technicaldetails.htmNotice it has two types of anchors rated for the same size boat, the only difference is one is aluminum and the other steel. They are rated the same because the surface area for resistance is the same. (but quietly they will admit that the steel will set a bit quicker or easier in tough conditions - ie. sea grass etc. Due to the extra weight being able to peirce through to the sea bottom)http://www.spade-anchor.co.uk/faqs.htmThere is no perfect anchor and some anchors are much better for some conditions than others, but the better ones hold and set in more conditions.FYI for full disclosure I now have a 44lb Spade Anchor and only 15 ft of 5/16 HT chain (yes a bit too short) on my 15,000++ lb. C36 and am very happy with it for my conditions. Some may say its a bit oversized, but I have a windlass. If I didn't I would probably have gone with the aluminum version. I have a 22lb danforth as a backup that I used for a year or two that I was satisfied with and wouldn't hesitate to use it....just as long as I made sure it was set well. I have used a CQR knockoff on an old boat and I was happy with it and from I've seen properly sized Delta's and Bruces are good too. I think the Spade's biggest weakness is in very thin, soupy mud which luckily is not too prevalent out on LI Sound. It does work very well in the LI "muck" (ala Oyster Bay), but the thiner the mud I think the less effective it is AND I really must hand it to the folks at Spade becuase they will at least admit its not their strongest point, but the real facts are its not most anchors strongest attribute. I think only adjustable anchors where the shaft angle can be modified to set the angle of the flukes to dig deeper in the mud (Like the Supermax and some types of danforths) are the only ones that seem to do really well in soupy mud. Those types of conditions seem to be mostly only prevalent in the deep south and bayous.But if I had to pick a 2nd anchor it would be the Bulwagga. The reasons being are the combination of very good holding power, not too heavy, can set & reset quickly also at a decent price (The Spade is a bit expensive). I think its biggest detriment is that it is not easy to mount with or without a bow roller and its a bit peculiar looking, but I think with some modifications you can make it work.http://www.noteco.com/bulwagga/letters.htmOne more note: Typically each foot of chain is only about 1 lb per foot. So 25 feet of 5/16HT chain would be just under 25lbs.