Mast Vertical Checking Question?

I have not been working on the boat project for over a month now, the last I had done was to power plane the trees down to size. One mast was ready for sanding, and the other was 75% done when my power plane melted it's little drive belt. I have since replaced the plane, an extended story in itself.

The plane is a discontinued model, and the belt I needed is also discontinued. However, because the product is not repairable due to this, they said I could replace it with a similar model, just bring it in with a receipt. It took me a while to locate the receipt, then drive to a store with stock, but they did a straight across the board exchange, with another identical old stock plane.

Other projects and a trip interrupted further work, and I went out to look at the masts today, and I found a lot of vertical checking. The question I have is how much checking is too much? Buehler's Backyard Boatbuilding makes it sound like the checks are no big deal, but he was also talking about a mast that had been oiled. I also ask, if this mast is considered OK, do I just go ahead, finish sanding and paint it? Or would it be considered too weak, and I am better off to start over with a fresh tree?

Feedback from anyone with mast making experience is welcome, as this is the first tree I have attempted to make into a mast.

Note the spiral checking, really obvious on the one mast, I believe this is why the lumber guys left it for the firewood guys, hard to make a straight board from it. I think it is Tamarack, but am not 100% sure.
   
The tamarack or hackmatack has been an excellent timber much used for ships. It is practically indestructible under water and stands very well even where exposed. It is used to be the colonial substitute for the ‘compass timber’ of English oak used in the ships of the Royal Navy, it’s roots furnishing the natural knees and other curved pieces so precious to the early shipbuilders. Unfortunately the tamarack as a commercial timber is no more, for some years ago an insect pest swept the country and destroyed all the trees of any size. Their gaunt skeletons, bare, grey and dry as tinder, may still be seen standing in northern bogs and muskegs, a tribute to the species durability. Fortunately new growth is rapidly coming on. (Lower, A. 1938)

Organic Carbon Fibre Masts, August 2016

Here is an update for August, 2016. I picked up my 

trees, and have done the rough work of converting them to "Organic Carbon Fibre" Masts. Of course, this is only going by what my high school biology teacher told me trees were made of, with a few years in between to make the memories a little fuzzy. Anyways, it is much easier to let Mother Nature do the layup of the carbon fibre than doing it myself.
Also had to build some heavy duty saw horses for this step.  

 I have the best pole completely power planed as the main mast, and the second best pole about 70% done, before the belt in my planer melted. I have just exchanged it on warranty, as the planer and replacement belt are discontinued, but one local store had some of the old stock still.
Next is to take the belt sander to  the poles, cut to length, and put on a coat of paint.
There is a third pole in case I find major flaws in the first two.

 I also bought two 50 gallon water tanks, here is a picture of the starboard tank in position, and at the bottom of the picture is a corner of a 4" deep 37x37" tray that will form my shower pan. The pan will get a sump pump and an elevated grating to stand on while showering.

Not shown is a 32 gallon tank that will be installed for grey water, when in a location that does not allow discharge.







I purchased the various fittings to fill and vent, as well as a 8" clean out with rubber seal for each tank. Once I have the tanks and bulkheads all figured out, I will cut and install the fittings