I'm trying to get the most recent TankValue record for each tank.
var result =
from t in Tanks
join tv in TankValues on t.ID equals tv.TankID
group tv by new { t.ID, t.Description } into g
orderby g.Key.Description descending
select new {
Description = g.Key.Description,
LogDate = g.OrderByDescending(x => x.LogDate).FirstOrDefault(),
Level = g.OrderByDescending(x => x.LogDate).FirstOrDefault().LevelPercentTotal
};