Laying a foundation, need help...

I am a relatively new resident to Second Life (have been in other Virtual Worlds for some time: AC, DAoC, AO, PE, EVE, etc) and am very impressed with the user built content that SL has to offer not to mention the fact that user content is the norm instead of the exception as in other virtual worlds.

Purchased a parcel of land ('ell of a deal, but then maybe that is why the realtor wanted to know if I had ever been scuba-diving, it is completely under water). It is large enough to allow for a a fair amount of Prims, and my plan is to use it to experiment then to split off part and get down to what I really need for a humble abode. Anyway...

Have created several of the items that I need to create the structure that I want to build, however when I try to place the first piece (the foundation if you will), it disappears into my lost and found folder and I can not seem to get it to stay where I put it. Is there some trick to this that I am missing? Have looked through the Starter Guide as well as the FAQ and Knowledge Base, but am undable to figure this out or find any useful information that hints at what I am doing wrong.

I would wonder if it is because I am trying to build underwater but have seen other permanent structures underwater. And don't worry I will not be cluttering up the surface, as most of the structure will remain well under the surface, with only one small area projecting up through the surface. Do I need to somehow link it to the land? I assumed that if you Lock it and implement Physics on the object that it should work, however I have also tried not using either and both of these as well but with the same results. I have also tried various changes to positioning so as to make the object barely contact the ground, to have it embeded into the ground, as well as a few other things, but again it didn't work the way I expected. Even made modifications ot the land (flattening it, etc.), but again no luck.

Any suggestions or hints that anyone can provide would be much appreciated.

If the structure is meant to sit still, you don't implement physics.

Yeah, you only want to turn physics on when you want the object to be movable.

Also, if the origin point (the coordinates in Position, below the Physics checkbox in the edit window) of the object is below 0.5 on the z axis, it'll go off-world and into your Lost & Found, regardless of whether or not it's intersecting the ground or not. I think this number used to be something a lot higher, like 5.0m, but testing just now seems to indicate 0.5 as the cutoff.

Also, if your object's origin point is inside the ground, it'll get returned too.

Talked to Lee Linden and found out that at levels below about 7m objects larger than 7 meters will not stay in place, but instead go to the Lost and Found folder of your inventory. He said that it is a bug that they have been dealing with since beta. He demonstrated this for me and I was able to down-size the base of my structure to make it work. It also would not have been a problem had I not been trying to build underwater (thus below the 7m point at which larger structures do not stay. Thanks for all the suggestions though.