1991 Whaler Drive Modification

[Sandor]

I may purchase a 1991 25' Walkaround with Whaler Drive and the surveyor said the Whaler Drive is "wet" according to his moisture meter. Because the drive is fully encapsulated there is no way to see what is going on inside. The boat is located in Florida and the surveyor is suggesting it may be "sweating" inside there and he advised to cut a hole in the drive and tap around with a screwdriver and make sure it's all solid. Then he recommends installing a waterproof hatch and drain plug. I am not familiar with the construction methods for the Whaler Drive, but the seller is planning to take his boat in and have them do the suggested work. Does anyone here have any experience with a "wet" whaler drive? If I'm going to buy this boat should I be concerned with the seller cutting into the drive, and request he not do it? Thanks!

[Phil T]

I recall reading the drive is foam filled. You can check with Boston Whaler Customer Service - Technical. https://www.bostonwhaler.com/marketing/contact-customer-service/ They are great.

The classic whalerdrive was desiged and fabricated by Boston Whaler. The 90's Van Lacker designed models with a "whalerdrive" were made for Boston Whaler by a vendor and not foam filled.

I am very skeptical of surveyors unless they are truly knowledgeable about classic Whalers. The boat design and construction is very different and many inspectors have no clue.

I would never cut open a Whaler unless it was completely waterlogged. The foam is bonded to the hull and deck skins and provides its structure.

There are several visual signs you may have a problem with a hull or whaler drive including inspecting any openings and observing the waterline of the boat at rest.

Take a few dozen photos and upload them to the cloud and add a link so we can see them.

[Phil T]

From Jim's extensive reference article:

Whaler Drive: The Whaler Drive molded appendage was constructed with the same foam-filled technique as the rest of the hull, and it added considerable reserve floatation to the boat. It was mechanically fastened to the transom with approximately a dozen bolts, augmented by six very large, long bolts that extended from the extreme aft face of the bracket, through the Whaler Drive, through the transom, and anchored inside the hull with metal backing plates. The joint between hull and Whaler Drive was sealed with caulk. Needless to say, the drive appendage was very securely fastened to the hull. The Whaler Drive extended the approximate keel and chine lines of the hull aft about 30-inches. The lower portions of the appendage ran in the water at speed, effectively extending the length of the hull and thereby adding drag and negating the less turbulent water advantage. Because it displaced water, it also added buoyancy (as distinct from floatation) to the stern of the hull, in effect compensating for its own weight and for the shift in weight of the engines farther aft. The static trim of the hull was therefore not changed much at all. Conventional outboard engine(s) could be mounted to it, locating the propeller about 30-inches aft of the boat. The Whaler Drive was a rather expensive option, and in some cases the cost might have led buyers to just get a larger boat with the standard transom.....

cf: http://continuouswave.com/whaler/reference/engineBrackets.html