I have a brand new Bravo 3 on my Searay (paid a fortune for it) It constantly is losing gear lube under any kind of load. Now it is having trouble shifting. It will somewhat engage in forward and then 15 seconds later thump fully in, throwing my passengers to the deck. Any thoughts

If it is brand new from merc then Get that drive in to shop for a check out while it is still in warranty.Keep in mind the oil bottle inside will go down some with normal use but it should not be going empty In a few hours if that is what it is doing. I have seen a small amount of B 1 & 3s loose a good amount of oil while under way because the seal around the prop shaft area would be bad from new and you would only loose the oil while under load and you could watch the oil bottle level drop down really fast and be empty in no time at all.