1993 Dauntless 15: Repower and gelcoat cracks

[adk_bearshark]

Last year I purchased a 1993 Dauntless 15 powered by a 2004 Yamaha 40-HP carburetor engine. I had no problems with the boat or engine, other than the boat was under-powered.

There are stress cracks running along the [topsides] of the gunwales, [but they are] cosmetic.

There is one soft spot on the hull where the skin and foam have (presumably) unbonded, and two small soft spots on the [cockpit deck].

I used [the 1993 DAUNTLESS 15] all last year for over 100 hours, and [the boat] seems fine.

I can tell there has been at least one major repair to the fiberglass--but I was not looking for a perfect boat.

Q1: is cruising around [in the 1993 DAUNTLESS 15 in the condition described above] alright?

Q2: [if I continue to cruise around] am I causing more damage [to the boat]?

Q3: if [this particular 1993 DAUNTLESS 150 were] your boat, what would you do?

I want to re-power [the 1993 DAUNTLESS 15] with a new Yamaha F70 at a cost of $7,200.

Q4: taking into consideration the soft hull spot and couple floor soft spots, how does a 1993 DAUNTLESS 15 perform with a Yamaha F70?

Q5: what is the top speed of a 1993 DAUNTLESS 15 with a Yamaha F70?

Q6: is the [improvement in performance due to] re-power [of a 1993 DAUNTLESS 15 with a new Yamaha F70] worth [the cost of the re-power]?

BACKSTORY: I work at a marina and do fiberglass and gel coat work on larger boats,typically 18-feet to 25-feet. I don't have experience with repairs to the deck or hull of Boston Whaler [Unibond hull] boats. My first forum post. I have learned and used a lot of information from here already. Thanks for that.

[biggiefl]

It is not going to do more damage by using it. Soft spots can be fixed relatively quickly. Repowering is your decision. I personally would fix it first and look for a nice used engine.

[jimh]

I don't have experience with repairs to the deck or hull of Boston Whaler [Unibond hull] boats.

For advice on making repairs to Boston Whaler boat Unibond hulls, I recommend you read several articles on that topic. Here are three in perhaps the most logical order to read:

INSTRUCTIONS -- HULL PATCH KITS
http://continuouswave.com/whaler/reference/repairInstructions.html

Repairing Hull Damage the Whaler Way
http://continuouswave.com/whaler/reference/whalerRepair.html

The Epoxy Cure
http://continuouswave.com/whaler/reference/epoxyRepair.html

A better understanding of the method of making a Unibond hull is conveyed in the original patent. See

Original Patent
of the Boston Whaler Hull Construction
http://continuouswave.com/whaler/refere ... atent.html

If you have specific questions about how to make a particular hull repair, please start a new thread in the REPAIRS AND MODIFICATIONS forum.

[jimh]

Q4: ...how does a 1993 DAUNTLESS 15 perform with a Yamaha F70?

A4: Generally the PERFORMANCE of a particular boat and engine combination would be discussed in the PERFORMANCE forum.

You can make an inference about the performance based on the specifications for maximum and minimum recommended power for the boat from catalogue listings.

There is one problem in looking for a 1993 DAUNTLESS 15: I cannot find any information for a 1993 model year boat. There is information for a 1994 DAUNTLESS 15.

Q7: what is the HIN number on this hull?

According to the Boston Whaler catalogue for 1994, the DAUNTLESS 15 needed a minimum of 30-HP, and a maximum of 70-HP was allowed. On that basis, performance of a DAUNTLESS 15 with 70-HP should be very good. The boat should reach plane easily and quickly.

Q5: what is the top speed of a 1993 DAUNTLESS 15 with a Yamaha F70?

A5: The top speed will be in proportion to the total weight of the boat, engine, fuel, gear, and crew combined. Starting with a bare hull weight of [Oops--not correct; see computation of speed in follow-up post below--jimh]

Q6: is the [improvement in performance due to] re-power [of a 1993 DAUNTLESS 15 with a new Yamaha F70] worth [the cost of the re-power]?

Only you can answer this. We don't know the cost; we don't know how important the speed increase will be to you. We don't know what value you will place of the speed increase or how dear the cost will be to you.

Speed increases with the square-root of power-to-weight, or to the 0.5 exponent, but outboard engine cost increases with horsepower at least linearly, that is to the 1.0 exponent if not exponentially, that is, to the 1.n exponent. On that fundamental relationship between more speed and more cost, it will always cost more to increase speed with more horsepower than you'd like it to.

As a general paradigm, buying a new (unused) outboard engine to re-power a boat that is 27-years-old is unlikely to increase the total value of the boat, engine, trailer, etc., by the same amount as the cost of the new engine minus any trade-in value for the old engine or income from selling the old engine. Re-powering is generally a luxury item.

[biggiefl]

I have always been puzzled by the early Dauntless and their weight. With a 1,200-lbs hull weight I would drop a 115 on that puppy. How do you build a 15-foot boat that weighs only 50-lbs less than my Outrage 18?

[B.E.Coyote]

I think it is the Dauntless 16 that weighs in at 1200 pounds and needs the 115. The extra 12" doesn't change your point though.

Hull for the Dauntless 15 is listed at 850 pounds. Still heavy.

[jimh]

Sorry for the confusion about the DAUNTLESS 15 hull weight. The actual specifications from the 1994 catalogue indicate a bare hull weight was 730-lbs.

Q5: what is the top speed of a 1993 DAUNTLESS 15 with a Yamaha F70?

Using a rough estimate of double the hull weight, we'd have say 1,500-lbs and 70-HP, which would suggest top speed around 39-MPH for a hull coefficient of 180, which seems reasonable for the newer V-hull design used in that era. Generally to go 39-MPH in a 15-foot boat you will need a calm sea state.

Here are two old and low-resolution motion-picture recordings of a classic SPORT 15 running about 24-MPH in some larger seas:

http://continuouswave.com/whaler/movies/153.mpg
http://continuouswave.com/whaler/movies/154.mpg

[adk_bearshark]

Thank you for the responses!! I’m going to go ahead with the repower hopefully early this year. I’m not interested in selling.

Jim-I have had the same trouble locating information on any 1993 15’ Dauntless. I typically only find the years 1994-1996 for this size. My biggest concern with this is I want to order matching gel coat so I can respray.

My hull ID is BWCHA226E393. Thanks again.

[jimh]

Thanks for posting the boat's federal hull identification number or HIN. As you may know, the HIN contains information about model year. I decode your boat's HIN according to the method I describe in the FAQ answer to Question-2 as follows:

BWC = the manufacturer identity code (MIC) for Boston Whaler
HA226 = a five-digit alpha-numeric produce code sequence number, prefix HA = 15 DA (DAUNTLESS) based on the HIN sequence chart
E = month of production was May
3 = year of production was 1993
93 = model year was 1993

On the basis of this HIN, it appears that this boat is a Boston Whaler 1993 DAUNTLESS 15 made in May 1993. Note that in the REFERENCE article, "Dimension and Production Information, All Models 9-31", the production epoch does denote 1993 as the first year of production.

The HA prefix was the first in the designated range of prefixes. The 226 indicates an early production model. Sometime production sequence numbers below 100 are used for prototype hulls, and regular production begins with 100 and increments upward.

[adk_bearshark]

Thanks for posting the boat's federal hull identification number or HIN. As you may know, the HIN contains information about model year. I decode your boat's HIN according to the method I describe in the FAQ answer to Question-2 as follows:

BWC = the manufacturer identity code (MIC) for Boston Whaler
HA226 = a five-digit alpha-numeric produce code sequence number, prefix HA = 15 DA (DAUNTLESS) based on the HIN sequence chart
E = month of production was May
3 = year of production was 1993
93 = model year was 1993

On the basis of this HIN, it appears that this boat is a Boston Whaler 1993 DAUNTLESS 15 made in May 1993. Note that in the REFERENCE article, "Dimension and Production Information, All Models 9-31", the production epoch does denote 1993 as the first year of production.

The HA prefix was the first in the designated range of prefixes. The 226 indicates an early production model. Sometime production sequence numbers below 100 are used for prototype hulls, and regular production begins with 100 and increments upward.

Very cool! I still haven't been able to find literature on this particular year though. Would you have a recommendation at where to look if I wanted to match the white gelcoat?

[jimh]

I recommend you contact Boston Whaler customer service at the factory in Edgewater, Florida. They should be able to tell you the gel coat color. But better call them soon, as the old-timers of Boston Whaler who know that sort of detailed information about older boats are starting to retire.

Most likely the gel coat color was originally a shade of nearly pure white, perhaps "Whaler White."

Also the custom-tint gel coat supplier SPECTRUM COLOR tends to have good information about Boston Whaler gel coat hues by model and model year. Call them, too.

[sinbad]

I have a [1996-always use four digits to specify a year; jimh] Dauntless 15, which should be the same as your [1993] boat. The factory brochure lists its weight as 850-lbs. Add my stern deck, cooler, anchor, radios, and other gear, and the wight probably gains 100- lbs. I am powered with the original Evinrude 60. I had some instances of limp home mode, probable overheating, late last season. (I didn't get a chance to see if new waterpump assembly, thermostat, temperature sensor, and vinegar flush fixed it.)

I looked into a new engine, and the Yamaha F70, and is similar sisters of 50 and 60 hp, are the only new engines that are not much heavier than the original Evinrude 60. The price you got was $2,000 less than I was quoted by a local Yamaha dealer at the Ocean City, MD boat show last weekend. I had asked to include a new throttle assembly and tachometer, expecting that mine were incompatible with Yamaha. Taylor Marine, the local Boston Whaler dealer I respect, advised me to wait to see if my Evinrude 60 engine was still broken. He felt it was not a cost effective decision to repower my [1996 boat] with a new engine. I've seen some old 60 or 70 hp Evinrudes on Craigslist in the range $800 to $1,500.

I plan to keep the boat at least three years because it is so easy to singlehand with the trailer, and my 1500 lb tow rated wagon. I may hand the boat down to one of the kids then, when my wife's schedule becomes much more open, and we simply keep whatever 20 to 22 footer we buy on our lift.

Top end with my 60 is about 5000 rpm, giving 28 knots (32 or so statute mph). I don't expect any big gain with the 4 stroke Yamaha 70. Perhaps I need a better prop selection. It rare that I run above the low 20's in our Bay, it gets too rough and the boat slams. The boat can take it, but I find it more than I want for any distance.

Good luck with your decision. I do like the boat, considering the size and weight.