Tiara 3100 Open
By Jack Hornor
Revised by BoatUS editors in October 2012
Noted for her superior quality construction and outstanding fishability, the Tiara 3100 Open is compared, in some circles, to the iconic 31 Bertram. And, although some would disagree with this comparison, most would agree the 3100 Open's quality, versatility and practicality is what kept her a popular model in Tiara's lineup for more than 25 years. The original 3100 Open was introduced in 1979 and was updated in 1992 with some style changes to the interior and new cockpit seating arrangements. The most significant change for 1992 and beyond models was a four-degree increase in the dead rise and the addition of "prop pockets" to the bottom. Although still very popular, earlier 3100s were known for their rather wet ride in choppy conditions, which was mitigated by the added dead rise. The shallow prop pockets help to reduce draft while, at the same time, lessening the angle of the propeller shaft resulting in more efficient propulsion. Unlike some manufacturers who rename or add "Mk II" to their models if they change the color of the boot stripe, Tiara kept the 3100 Open designation for the updated model and it remained in production through 2004.
In another departure from what has become many boatbuilders' propensity for inflating a model's size with a puffed up name, Tiara has taken the opposite approach. The overall length of the 3100 Open is actually 33' 10" which includes a bow pulpit that is part of the deck mold. Add to that another two feet for the swim platform, which was a common option, and the overall length of the boat is nearly 35 feet. Beam is an even 12 feet and the "hull draft" specified by the manufacturer's brochure is two feet two inches which does not include appendages such as rudders and propellers. I suspect the actual draft would be a little over three feet.
For the sake of brevity, I am not going to spend much time discussing the quality and method of construction of the 3100 Open other than to say that it ranks near the top of production boat manufacturers. Tiara is particularly well regarded for the quality of their fit and finishes and there are seldom problems relating to flaws in construction.
One related matter worth mentioning is the 2000 U.S. Coast Guard recall of several Tiara models, including the 3100 Open, not for a construction problem but for fuel system integrity. The recall involved 473 1983-1993 models including the 3100 Open, Flybridge and Convertible models equipped with a single fuel tank option offered by the company. The concern was for seawater that could become trapped beneath the fuel tank causing corrosion and eventual fuel leakage. The recall campaign was closed by the Coast Guard in 2004, with 464 of the potential problem-boats inspected and repaired where necessary, so there is only a very slim possibility of remaining problems. Owners or potential buyers of boats with single fuel tanks should check with the manufacturer who has records of all repairs.
The deck layout and arrangement are ideally suited for fishing and ease of handling. The molded fiberglass bow pulpit allows for convenient storage of the anchor, and although an option, most models are equipped with an electric anchor windless. The cabin top has three opening deck hatches but is otherwise unobstructed.
A variety of optional cockpit seating and locker arrangements were available but generally all models have a double helm seat to starboard with guest seating and lockers to port forward with a large open cockpit aft. Beginning in 1994 a transom door was included as standard equipment, a feature desired by many anglers.
The interior arrangement remained the same for both iterations of the 3100 Open with a starboard double berth forward, a U-shaped dinette to the starboard side of the main saloon with opposing galley and a head and shower aft to port. The most notable interior difference between the two models was the manner in which the forward cabin was separated from the main saloon. The early design featured a fixed bulkhead with bi-fold doors for privacy while, on the latter, a draw curtain was used. The curtain makes for less privacy but a more open and larger looking interior. The standard power package included twin 350-hp Crusader gasoline engines with twin 230-hp Volvo, 300-hp Caterpillar, or 315-hp Cummins diesel engines offered as options. My one serious complaint with this boat is that access for maintenance of machinery is very difficult and gets even worse with the addition of an optional auxiliary generator. With the various power options, cruising speed ranges from 20 to 23 knots with a top speed in the range of 33 knots. As previously mentioned, the earlier models have tendency to pound and be wet when weather conditions worsen. Although the later models don't compare to greater dead rise hull forms such as the 31 Bertram for comfort in rough seas, they are an improvement.
Naval architect Jack Hornor was the principal surveyor and designer for Marine Survey & Design, Co., based in Annapolis, MD. He was on the boards of the American Boat and Yacht Council, the National Association of Marine Surveyors, and the Society of Boat and Yacht Designers. He and his wife sailed their Catalina 42, Legacy, based on Maryland's Eastern Shore.