I'll have the maximum contribution to a Solo 401K met (53K) and have about the same amount or a little more left over that Ive saved this year.  What do I put it in?

House has 15 yrs left at 2.75%.
Boat loan at 4%...balance of about 38K,
No CC debt, car notes, etc.

Married, SE, 45yo, our total 2016 AGI is going to put us over the amount for contributing to a Roth (194K)

Is there any where else to invest/save for retirement that may provide some shelter?  Do I just throw it in a regular investment account?  Or do I pay off house/boat.

Pay down the boat, unless you've got a personal brokerage account or want to start a Roth, that will outearn the 4% on the boat loan.

Taxable account invested in ETFs.

I got ya buddy. You can still make a $5500 tax-deductible annual contribution to a Traditional IRA. Even though you are over the income threshold for contributions to a Roth IRA, you can also still make a non-deductible contribution to a Traditional IRA, and then convert that Traditional IRA contribution into a Roth IRA. $5500 annual limit, of course. End result would be the same as a typical Roth contribution. This is called a "back-door" Roth IRA contribution.

As far as the investments go, I can't really tell you what you should invest in without knowing more information. What is your risk tolerance? How long do you plan to invest? When do you plan to retire? What type of income do you anticipate you will need in retirement? What are your liquidity needs? What are the returns you would like to see with your investments? What type of investment strategy do you have in place currently? What type of market exit strategy do you currently have in place? How closely does your current investment strategy match your investment goals?

^This. Paying the boat off may seem good, but from a pure financial planning standpoint, it would be better to invest that money instead of paying off that boat loan, and there are several reasons. Firstly being liquidity. You would then have the boat paid off, but the money you used paying off the loan cannot be used for anything else. It is much more difficult to sell the boat than it would be to simply withdraw that money after selling a few investments. Secondly, opportunity cost. You could invest that money rather than pay off the boat at a market return of ~7% benchmark, provided there is no global financial crisis. That return far exceeds the 4% you are paying on interest on that loan. This also gives you much more liquidity. The same would go for the mortgage.

pay off the boat, buy brk

Get rid of intrest payments that are not tax deductable.

Boat payment needs to go...

Then normal stuff, roth IRA, brokerage acct, and so on.

I'd split between the boat and a taxable account. A guaranteed 4% ROI by paying of the boat is nothing to sneeze at.

build a taxable investment account.  It will allow you to have liquidity if you need money before 59 1/2.  You can minimize your taxes on growth by using municipal bonds, dividend paying stocks, and reits.

Now with regards to the boat loan, it depends on the interest rate.  If the rate is above 5%, you might want to consider paying that down as well.
If it's low, than take advantage of the cheap money, and invest.  Unless your risk tolerance is conservative, there is not need to pay down cheap debt.  Debt allows you to have leverage, and as long as you are smart, and responsible with leverage, take advantage of it.

Now, another option would be to do a defined benefit plan for yourself.  You can defer up to $250k per year.  however, you need to follow a ten year schedule.

What kind of boat did you buy?

You can perform back door Roth conversions for you and your wife, $11k each year.  Just be aware of the pro rata rule when converting.

This is how you win at life.

Can someone explain this more? I max out my Roth and my IRA. I didn't know you could also do $5500 into a Traditional IRA.

 
You can't, he's saying $5.5k for each of the OP and OP's spouse

Damn. That's what I thought. Thanks.

are you married?