Depends a bit on what was meant by three feet at low tide. If it's official chart reading low water springs then under most circumstances you will have more than three feet depending of course on how much variation there are in the tides for your area.
(late edit) I based the above on you having plenty of water in the slip itself and on the presumption that the three foot depth is only at the entrance to the marina itself. If the three feet is in the slip itself then you have problems.
“Give a man a fire and he's warm for a day, but set fire to him and he's warm for the rest of his life.” Terry Pratchett
Last edited by tdw; 02-15-2007 at 07:00 PM.