I do like ratcheting double crimpers for insulated PIDG style terminals, yellow, blue & red. However I do not use them on heat shrink crimps because you don't need the second strain relief crimp like you do with a non-heat shrink terminal. Using a double crimper on heat shrink crimps can cause them to rip too and when they cost between .25 & 1.00 each using the right tool pays you back. 98% of the terminals I install these days are heat shrink crimp because they are just so damn reliable. Single crimp ratchet tools are designed only for heat shrink crimps and doubles like the Ancor are designed for regular insulated terminals.

Now my expensive AMP crimpers can do both double and single crimps because the strain relief can be adjusted out of the way so as not to impact the heat shrink and ruin it. There are not many boaters out there though who are willing to cough up anywhere near what would be needed to buy the two AMP tools I use but then most boaters don't do marine wiring as a side business.

What ever you do just don't use those all in one cut, strip & crimp tools. They lack the leverage and design to make repeatable and reliable crimps.

A good value for a crimp tool that does both is the Pro's Kit CP=371 Pro Frame $26.67 + a single crimp die #: 9PK-3003D27 $16.67 and a double crimp die #: 9CP-236DH $13.75

http://www.proskit.com/crimpers/frames/CP-371

While the Ancor double ratchet tool will hold roughly 40 pounds more in load tests with 12 GA wire, the Pro's Kit will still hold more than double the ABYC requirement for pull out force. The Ancor is a well made tool and repeatedly bested the Harbor Freight double crimper and the Pro's Kit by a wide margin in sheer crimp holding power. The two all in one tools I tested only once exceeded the ABYC requirement of 35 pounds and I went through about 20+ yellow crimp terminals testing them. The Ancor tool can hold into the 120's....