CONTINUOUSWAVE

[The author may buy a 1999 OUTRAGE 18 powered by a Tohatsu 150-HP four-stroke-power-cycle engine, and asks the following questions;}

Q1: is a 150-HP four-stroke-power-cycle engine right at the edge of adequate for a 1999 OUTRAGE 18 due to the hull's weight?

This question is based on comments regarding the power band of four-stroke-power-cycle engines from many years ago.

Q2: how much change in performance will occur with a 1999 OUTRAGE 18 with eight people aboard compared to with two people aboard?

Q3: with the 150-HP four-stroke-power-cycle engine, how will a 1999 OUTRAGE 18 perform with eight people aboard?

BACKSTORY

The latest boat I have considered in my quest to find a good Boston Whaler boat for my family was an 1999 Outrage 18. I understand this model is considered a post-classic, and it only was produced for a couple years. The fellow who is selling it bought it new in 1999, and has taken good care of it. Perhaps the best selling point is a brand new 2026 Tohatsu 150-HP [four-stroke-power-cycle engine] has been installed and currently has 10 hours run time. I sea-trialed the boat yesterday, and it ran like a dream. The [engine power] felt very strong getting the boat out of the hole, but that was with just two of us aboard. I have read in past posts that a 150-HP enhine might be right at the edge of adequate for this boat due to its weight, but those posts were from many years ago when four-stroke-power-cycle engine technology may not have been as refined as it is today.

Of course I wasn't able to bring six people on board to test [with a total of eight people aboard]; I wonder how performance may differ once the boat is loaded with a group of people and gear?

The asking price is high for a 27-year-old boat at $38,000. I do not want to purchase the boat just to realize it is underpowered.

Consider the weight of yourself and six guest anglers, a full tank of fuel, tackle, fenders, lines, etc and you are looking at quite a load for an 18 foot boat. Perhaps you should consider a larger boat or fewer guests. For a comfortable angling experience I believe four guests would be a better fit on that Outrage, regardless of the horsepower.

[To clarify the usage of the boat,] most of the time there will just be my family of four--two adults and two young kids--aboard the 1999 OUTRAGE 18. Only a few times a year will we want to bring along another couple people for a cruise.

I imagine that eight people aboard will be he maximum, but four would be kids.

Eventually they won't be kids, but by then who knows if they'll even want to go boating.

The boat seemed to have ample space for that array of people.

I don't actually fish that much.

[Moderators note: A proposed survey question which would determine how many readers of this thread own the particular boat under discussion has been deleted. Survey questions are not particularly useful because the number of participants tends to be very small considering the hundreds of thousands of people who own Boston Whaler boats. Please do not propose surveys.]

The answers to Q1, Q2, and Q3 all depend on additional information not available from the initial posts.

In boats, all performance occurs based on the ratio of power to weight. In smaller boats, a significant influence on the total weight of the boat will be the number of people aboard. This occurs because the dry or light weight of the boat with no one aboard is not particularly large.

The dry weight of a c.1999 OUTRAGE 18 hull has not been provided by the thread initiator. Without this information, discussing how adding passenger weight will affect the boat performance is impossible. Accordingly, some research on-line suggests the dry weight of a c.1999 OUTRAGE 18 is 2,500-lbs. Also, there has been no information provided about the maximum power rating of the hull. Accordingly, some research on-line suggests the c.1999 OUTRAGE 18 is rated for 200-HP maximum. Also not provided is the minimum power rating, which, again from some online research, appears to be 115-HP.

We can make a rough approximation of the total weight of an c.1999 OUTRAGE 18 as follows (all weights in lbs):

• dry hull = 2,500
• 150-HP engine = 400
• rigging and standard gear = 250
• fuel = 250
• two passengers = 400
• gear = 200
• TOTAL = 4,000-lbs

Now we can predict the maximum boat speed for that weight and power, using the Crouch method (and my Crouch's Calculator with a hull factor of 180): 35-MPH
( Cf.: https://continuouswave.com/calculators/crouchCalc.php )

Next, we add the weight of two more adults (+400) and four more "kids" (+500), and recalculate the top speed using a total weight of 4,900-lbs: 31-MPH

The predicted top speed for the maximum passenger load case is thus lower by 4-MPH, but the unanswered question in this assessment: will the engine be able to accelerate onto plane with the heavier load?

A huge factor in this question is the propeller being used. In order to get the hull onto plane with the addition of 900-lbs of passengers, the propeller must be chosen for this particular loading, that is, the propeller pitch will need to be reduced from the best speed choice that would be made for the two-person load situation.

A reasonable assumption: an 1999 OUTRAGE 18 with 150-HP engine will certainly be able to reach plane with two adults and two small kids, but if the passenger load is increased to four adults and four small kids, the boat may have trouble reaching plane and a different (lower-pitch) propeller will need to be installed when the boat is used in that manner. The "maximum" load propeller will probably need to be 2-inches-lower pitch than the standard-load propeller.

JoeNorm wrote:The asking price is high for a 27-year-old boat at $38,000.

Many more elements than just the age of the hull affect the selling price of Boston Whaler boats. Not mentioned by the thread initiator is what else is included in the proposed purchase. Items such as:

• a suitable and road-ready trailer
• electronics like a VHF Marine Band modern DSC radio, a chart plotter, a SONAR
• canvas such as Flying Top, Mooring Cover, Sun Top, and other Weather Canvas
• desirable gear such as anchor, cooler, fenders, lines, boarding ladder
• the gel coat condition
• the presence or lack of hull bottom water proofing with epoxy paint
• the presence or lack of anti-fouling bottom paint

All will affect the asking price and value of the boat-engine-trailer-gear-accessory combination of a particular used boat offered for sale. Thus, to dismiss the asking price as "high" may be inappropriate if the boat is in excellent condition and very well-rigged and equipped.

Certainly the 2026 engine and very limited engine use are significant influences on the asking price.

ASIDE
Were I a potential buyer, I would ask the seller why he invested in a new 2026 engine but now wants to sell the boat. Maybe he is not happy with the performance.

Re eight people--four adults and four kids--on an 18-foot boat: you better be very good friends with very well-behaved children, and you will need considerable patience from everyone.