Tunnel hull designs are pretty popular for modern bay boats. So, what are their advantages and disadvantages? And most importantly, are they right for you?
Many anglers mistakenly think that a tunnel hull boat will be able to get on plane in shallower water than a V-hull. In fact, their main advantage is to be able to run through shallower water, with the motor set higher than a V-hull, usually by raising it on a jackplate. The idea of the tunnel isn’t to eliminate that V protruding down into the water, as much as it is to “feed” a clean, solid flow of water to a propeller that’s above the boat’s waterline. As a result, a well-designed tunnel boat can skim over flats and bars with just a few inches of water. But make no mistake; if the boat’s sitting on such a shoal, it won’t be able to hop onto plane. In order to do so you’ll still need a good nine inches to a foot of depth, so the prop can be lowered enough to get a solid bite from a static position.
In some cases, tunnel boats also provide a smoother ride than V hulls or flat bottom boats. Like a powercat, they can compress a cushion of air in the tunnel, softening the blows as you hit waves or cruise over a chop.
But yes, there is a price to pay for the tunnel boat’s performance enhancements – usually as a matter of simple dollars and cents. Tunnels are complex forms that require a boatbuilder extra time and materials to mold into the boat. As a result, they can cost notably more then V or semi-V hull boats. Tunnel boats also have to be custom-matched to trailers that fit their footprint, which again can raise the cost of the package. Another down-side to taking the tunnel route is a loss of stowage space. Centered fishboxes or compartments don’t have that V to go down in to, so they’re likely shallower and smaller than they might otherwise be. Finally, some tunnel boats require a four-blade prop to get a solid grip on the water, especially when the motor’s jacked up. You may want to run a four-blade anyway, for its enhanced hole-shot and mid-range performance, but if you’re all about wringing every MPH of top-end speed from your boat, a four-blade isn’t going to be your first choice.
The bottom line: if you need to cruise over very shallow flats while on plane with regularity, a tunnel boat is probably an excellent choice. Otherwise, more traditional hullforms are likely to be your best bet.