Odors originate from three main sources. Diesel/engine room odor, head and holding tank odors, and mold and boat mildew.
Consult your local mechanic to address the diesel /engine odors. Possibilities include and fuel leak, exhaust leak, or blow by which inflicts older engines as compression deteriorates and intake can generate a bit of a fog. Your mechanic will have suggestions from aftermarket intake separators to engine overhauls.
First step to investigate head odors is the obvious leak. This does not need to be large to cause a real problem. Next would be hose permeation. Waist odors will migrate through the best of hoses when waist is allowed to sit in the hose. To test, find a dip in the hose where waist may linger. Clean the hose and place a warm wet rag on the hose and leave it for 30 minutes. Smell the rag, is that the odor you find in the boat? If so the only solution is to replace the hoses.
Now for the tough problem, boat mildew, mold and the general musty smell. Removing mold is the key. You have likely found black mold spots on areas of you boat and quickly removed them as we all know Black mold is toxic. Unfortunately, the areas of you boat you cannot inspect are the most likely locations for Black mold to thrive. Removing mold is not difficult but it requires the proper technology. First step is a thorough bilge cleaning. Start a complete bilge cleaning using the available bilge cleaner that can be added to the bilge next time you are out in the water. Bilge cleaning will be a good start but to eliminate the odor you must treat with Chlorine Dioxide. I recommend Odor Watch Solution. This is a 100 gram package to produce a solution of Chlorine dioxide in and water. Chlorine Dioxide is highly effective for killing and removing mold. Drain the bilge cleaner as per the instructions from the manufacture and fill the bilge with the Chlorine Dioxide solution. I recommend using the Bilge Snake from Boater Tech to agitate and reach every corner of you bilge. This is likely where the mold is. Agitate with the bilge snake for 30 min. or take the boat out to create agitation. Agitation is not required for Chlorine Dioxide to work. It’s needed to simply get the solution in contact with all surfaces of the bilge. Leave the solution in place overnight. Drain the bilge once the water no longer has a yellow tinge. The yellow coloring is a sign that there is active Chlorine dioxide in the solution. No rinsing is required.
Last step and most important is to use Odor Watch 24/7 to guard against mold returning. Odor Watch 24/7 provides a safe but effective level of Chlorine Dioxide while you are away from your boat. Simply close the container when you are on the boat (so not to waste product) or you can keep it open as the low level of Chlorine Dioxide is safe for pets and people. I recommend you close the container since you will likely have air flow below while guests are on board and Chlorine Dioxide will not be effective. Open the container when you close the boat up and leave.
You will be pleasantly surprised when you and your guests return for your next outing.
